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/* pdp18b_cpu.c: 18b PDP CPU simulator
Copyright (c) 1993-2008, Robert M Supnik
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
ROBERT M SUPNIK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Except as contained in this notice, the name of Robert M Supnik shall not be
used in advertising or otherwise to promote the sale, use or other dealings
in this Software without prior written authorization from Robert M Supnik.
cpu PDP-4/7/9/15 central processor
28-Apr-07 RMS Removed clock initialization
26-Dec-06 RMS Fixed boundary test in KT15/XVM (Andrew Warkentin)
30-Oct-06 RMS Added idle and infinite loop detection
08-Oct-06 RMS Added RDCLK instruction
Fixed bug, PC off by one on fetch mem mmgt error
PDP-15 sets API 3 on mem mmgt trap (like PI)
PDP-15 sets API 4 on CAL only if 0-3 inactive
CAF clears memory management mode register
27-Jun-06 RMS Reset clears AC, L, and MQ
22-Sep-05 RMS Fixed declarations (Sterling Garwood)
16-Aug-05 RMS Fixed C++ declaration and cast problems
22-Jul-05 RMS Removed AAS, error in V1 reference manual
06-Nov-04 RMS Added =n to SHOW HISTORY
26-Mar-04 RMS Fixed warning from -std=c99
14-Jan-04 RMS Fixed g_mode in XVM implementation
PDP-15 index, autoincrement generate 18b addresses
Revised IO device call interface
31-Dec-03 RMS Fixed bug in cpu_set_hist
02-Nov-03 RMS Changed PDP-9,-15 default to API
26-Oct-03 RMS Fixed bug in PDP-4,-7,-9 autoincrement addressing
19-Sep-03 RMS Changed instruction history to be dynamically sized
31-Aug-03 RMS Added instruction history
Fixed PDP-15-specific implementation of API priorities
16-Aug-03 RMS Fixed PDP-15-specific handling of EAE unsigned mul/div
27-Jul-03 RMS Added FP15 support
Added XVM support
Added EAE option to PDP-4
Added PDP-15 "re-entrancy ECO"
Fixed memory protect/skip interaction
Fixed CAF not to reset CPU
12-Mar-03 RMS Added logical name support
18-Feb-03 RMS Fixed three EAE bugs (Hans Pufal)
05-Oct-02 RMS Added DIBs, device number support
25-Jul-02 RMS Added DECtape support for PDP-4
06-Jan-02 RMS Revised enable/disable support
30-Dec-01 RMS Added old PC queue
30-Nov-01 RMS Added extended SET/SHOW support
25-Nov-01 RMS Revised interrupt structure
19-Sep-01 RMS Fixed bug in EAE (Dave Conroy)
17-Sep-01 RMS Fixed typo in conditional
10-Aug-01 RMS Removed register from declarations
17-Jul-01 RMS Moved function prototype
27-May-01 RMS Added second Teletype support, fixed bug in API
18-May-01 RMS Added PDP-9,-15 API option
16-May-01 RMS Fixed bugs in protection checks
26-Apr-01 RMS Added device enable/disable support
25-Jan-01 RMS Added DECtape support
18-Dec-00 RMS Added PDP-9,-15 memm init register
30-Nov-00 RMS Fixed numerous PDP-15 bugs
14-Apr-99 RMS Changed t_addr to unsigned
The 18b PDP family has five distinct architectural variants: PDP-1,
PDP-4, PDP-7, PDP-9, and PDP-15. Of these, the PDP-1 is so unique
as to require a different simulator. The PDP-4, PDP-7, PDP-9, and
PDP-15 are "upward compatible", with each new variant adding
distinct architectural features and incompatibilities.
The register state for the 18b PDP's is:
all AC<0:17> accumulator
all MQ<0:17> multiplier-quotient
all L link flag
all PC<0:x> program counter
all IORS I/O status register
PDP-7, PDP-9 EXTM extend mode
PDP-15 BANKM bank mode
PDP-7 USMD trap mode
PDP-9, PDP-15 USMD user mode
PDP-9, PDP-15 BR bounds register
PDP-15 RR relocation register
PDP-15 XVM MMR memory management register
PDP-15 XR index register
PDP-15 LR limit register
The PDP-4, PDP-7, and PDP-9 have five instruction formats: memory
reference, load immediate, I/O transfer, EAE, and operate. The PDP-15
adds a sixth, index operate, and a seventh, floating point. The memory
reference format for the PDP-4, PDP-7, and PDP-9, and for the PDP-15
in bank mode, is:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| op |in| address | memory reference
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
The PDP-15 in page mode trades an address bit for indexing capability:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| op |in| X| address | memory reference
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
<0:3> mnemonic action
00 CAL JMS with MA = 20
04 DAC M[MA] = AC
10 JMS M[MA] = L'mem'user'PC, PC = MA + 1
14 DZM M[MA] = 0
20 LAC AC = M[MA]
24 XOR AC = AC ^ M[MA]
30 ADD L'AC = AC + M[MA] one's complement
34 TAD L'AC = AC + M[MA]
40 XCT M[MA] is executed as an instruction
44 ISZ M[MA] = M[MA] + 1, skip if M[MA] == 0
50 AND AC = AC & M[MA]
54 SAD skip if AC != M[MA]
60 JMP PC = MA
On the PDP-4, PDP-7, and PDP-9, and the PDP-15 in bank mode, memory
reference instructions can access an address space of 32K words. The
address space is divided into four 8K word fields. An instruction can
directly address, via its 13b address, the entire current field. On the
PDP-4, PDP-7, and PDP-9, if extend mode is off, indirect addresses access
the current field; if on (or a PDP-15), they can access all 32K.
On the PDP-15 in page mode, memory reference instructions can access
an address space of 128K words. The address is divided into four 32K
word blocks, each of which consists of eight 4K pages. An instruction
can directly address, via its 12b address, the current page. Indirect
addresses can access the current block. Indexed and autoincrement
addresses can access all 128K.
On the PDP-4 and PDP-7, if an indirect address in in locations 00010-
00017 of any field, the indirect address is incremented and rewritten
to memory before use. On the PDP-9 and PDP-15, only locations 00010-
00017 of field zero autoincrement; special logic will redirect indirect
references to 00010-00017 to field zero, even if (on the PDP-9) extend
mode is off.
The EAE format is:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| 1 1 0 1| | | | | | | | | | | | | | | EAE
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| | | | | | | | | | | | | |
| | | | | | | | | | | | | +- or SC (3)
| | | | | | | | | | | | +---- or MQ (3)
| | | | | | | | | | | +------- compl MQ (3)
| | | | | | | | \______________/
| | | | | | | | |
| | | | | \_____/ +--------- shift count
| | | | | |
| | | | | +---------------------- EAE command (3)
| | | | +---------------------------- clear AC (2)
| | | +------------------------------- or AC (2)
| | +---------------------------------- load EAE sign (1)
| +------------------------------------- clear MQ (1)
+---------------------------------------- load link (1)
The I/O transfer format is:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| 1 1 1 0 0 0| device | sdv |cl| pulse | I/O transfer
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
The IO transfer instruction sends the the specified pulse to the
specified I/O device and sub-device. The I/O device may take data
from the AC, return data to the AC, initiate or cancel operations,
or skip on status. On the PDP-4, PDP-7, and PDP-9, bits <4:5>
were designated as subdevice bits but were never used; the PDP-15
requires them to be zero.
On the PDP-15, the floating point format is:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| 1 1 1 0 0 1| subopcode | floating point
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|in| address |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
Indirection is always single level.
On the PDP-15, the index operate format is:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| 1 1 1 0 1| subopcode | immediate | index operate
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
The index operate instructions provide various operations on the
index and limit registers.
The operate format is:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| 1 1 1 1 0| | | | | | | | | | | | | | operate
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| | | | | | | | | | | | |
| | | | | | | | | | | | +- CMA (3)
| | | | | | | | | | | +---- CML (3)
| | | | | | | | | | +------- OAS (3)
| | | | | | | | | +---------- RAL (3)
| | | | | | | | +------------- RAR (3)
| | | | | | | +---------------- HLT (4)
| | | | | | +------------------- SMA (1)
| | | | | +---------------------- SZA (1)
| | | | +------------------------- SNL (1)
| | | +---------------------------- invert skip (1)
| | +------------------------------- rotate twice (2)
| +---------------------------------- CLL (2)
+------------------------------------- CLA (2)
The operate instruction can be microprogrammed to perform operations
on the AC and link.
The load immediate format is:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| 1 1 1 1 1| immediate | LAW
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
<0:4> mnemonic action
76 LAW AC = IR
This routine is the instruction decode routine for the 18b PDP's.
It is called from the simulator control program to execute
instructions in simulated memory, starting at the simulated PC.
It runs until 'reason' is set non-zero.
General notes:
1. Reasons to stop. The simulator can be stopped by:
HALT instruction
breakpoint encountered
unimplemented instruction and STOP_INST flag set
nested XCT's
I/O error in I/O simulator
2. Interrupts. Interrupt requests are maintained in the int_hwre
array. int_hwre[0:3] corresponds to API levels 0-3; int_hwre[4]
holds PI requests.
3. Arithmetic. The 18b PDP's implements both 1's and 2's complement
arithmetic for signed numbers. In 1's complement arithmetic, a
negative number is represented by the complement (XOR 0777777) of
its absolute value. Addition of 1's complement numbers requires
propagating the carry out of the high order bit back to the low
order bit.
4. Adding I/O devices. Three modules must be modified:
pdp18b_defs.h add interrupt request definition
pdp18b_sys.c add sim_devices table entry
*/
#include "pdp18b_defs.h"
#define SEXT(x) ((int32) (((x) & SIGN)? (x) | ~DMASK: (x) & DMASK))
#define UNIT_V_NOEAE (UNIT_V_UF + 0) /* EAE absent */
#define UNIT_V_NOAPI (UNIT_V_UF + 1) /* API absent */
#define UNIT_V_PROT (UNIT_V_UF + 2) /* protection */
#define UNIT_V_RELOC (UNIT_V_UF + 3) /* relocation */
#define UNIT_V_XVM (UNIT_V_UF + 4) /* XVM */
#define UNIT_V_MSIZE (UNIT_V_UF + 5) /* dummy mask */
#define UNIT_NOEAE (1 << UNIT_V_NOEAE)
#define UNIT_NOAPI (1 << UNIT_V_NOAPI)
#define UNIT_PROT (1 << UNIT_V_PROT)
#define UNIT_RELOC (1 << UNIT_V_RELOC)
#define UNIT_XVM (1 << UNIT_V_XVM)
#define UNIT_MSIZE (1 << UNIT_V_MSIZE)
#define OP_KSF 0700301
#define HIST_API 0x40000000
#define HIST_PI 0x20000000
#define HIST_PC 0x10000000
#define HIST_MIN 64
#define HIST_MAX 65536
#define HIST_M_LVL 0x3F
#define HIST_V_LVL 6
typedef struct {
int32 pc;
int32 ir;
int32 ir1;
int32 lac;
int32 mq;
} InstHistory;
#define XVM (cpu_unit.flags & UNIT_XVM)
#define RELOC (cpu_unit.flags & UNIT_RELOC)
#define PROT (cpu_unit.flags & UNIT_PROT)
#if defined (PDP4)
#define EAE_DFLT UNIT_NOEAE
#else
#define EAE_DFLT 0
#endif
#if defined (PDP4) || defined (PDP7)
#define API_DFLT UNIT_NOAPI
#define PROT_DFLT 0
#define ASW_DFLT 017763
#else
#define API_DFLT 0
#define PROT_DFLT UNIT_PROT
#define ASW_DFLT 017720
#endif
int32 M[MAXMEMSIZE] = { 0 }; /* memory */
int32 LAC = 0; /* link'AC */
int32 MQ = 0; /* MQ */
int32 PC = 0; /* PC */
int32 iors = 0; /* IORS */
int32 ion = 0; /* int on */
int32 ion_defer = 0; /* int defer */
int32 ion_inh = 0; /* int inhibit */
int32 int_pend = 0; /* int pending */
int32 int_hwre[API_HLVL+1] = { 0 }; /* int requests */
int32 api_enb = 0; /* API enable */
int32 api_req = 0; /* API requests */
int32 api_act = 0; /* API active */
int32 memm = 0; /* mem mode */
#if defined (PDP15)
int32 memm_init = 1; /* mem init */
#else
int32 memm_init = 0;
#endif
int32 usmd = 0; /* user mode */
int32 usmd_buf = 0; /* user mode buffer */
int32 usmd_defer = 0; /* user mode defer */
int32 trap_pending = 0; /* trap pending */
int32 emir_pending = 0; /* emir pending */
int32 rest_pending = 0; /* restore pending */
int32 BR = 0; /* mem mgt bounds */
int32 RR = 0; /* mem mgt reloc */
int32 MMR = 0; /* XVM mem mgt */
int32 nexm = 0; /* nx mem flag */
int32 prvn = 0; /* priv viol flag */
int32 SC = 0; /* shift count */
int32 eae_ac_sign = 0; /* EAE AC sign */
int32 SR = 0; /* switch register */
int32 ASW = ASW_DFLT; /* address switches */
int32 XR = 0; /* index register */
int32 LR = 0; /* limit register */
int32 stop_inst = 0; /* stop on rsrv inst */
int32 xct_max = 16; /* nested XCT limit */
#if defined (PDP15)
int32 pcq[PCQ_SIZE] = { 0 }; /* PC queue */
#else
int16 pcq[PCQ_SIZE] = { 0 }; /* PC queue */
#endif
int32 pcq_p = 0; /* PC queue ptr */
REG *pcq_r = NULL; /* PC queue reg ptr */
int32 hst_p = 0; /* history pointer */
int32 hst_lnt = 0; /* history length */
InstHistory *hst = NULL; /* instruction history */
t_bool build_dev_tab (void);
t_stat cpu_ex (t_value *vptr, t_addr addr, UNIT *uptr, int32 sw);
t_stat cpu_dep (t_value val, t_addr addr, UNIT *uptr, int32 sw);
t_stat cpu_reset (DEVICE *dptr);
t_stat cpu_set_size (UNIT *uptr, int32 val, char *cptr, void *desc);
t_stat cpu_set_hist (UNIT *uptr, int32 val, char *cptr, void *desc);
t_stat cpu_show_hist (FILE *st, UNIT *uptr, int32 val, void *desc);
void cpu_caf (void);
void cpu_inst_hist (int32 addr, int32 inst);
void cpu_intr_hist (int32 flag, int32 lvl);
int32 upd_iors (void);
int32 api_eval (int32 *pend);
t_stat Read (int32 ma, int32 *dat, int32 cyc);
t_stat Write (int32 ma, int32 dat, int32 cyc);
t_stat Ia (int32 ma, int32 *ea, t_bool jmp);
int32 Incr_addr (int32 addr);
int32 Jms_word (int32 t);
#if defined (PDP15)
#define INDEX(i,x) if (!memm && ((i) & I_IDX)) \
x = ((x) + XR) & DMASK
int32 Prot15 (int32 ma, t_bool bndchk);
int32 Reloc15 (int32 ma, int32 acc);
int32 RelocXVM (int32 ma, int32 acc);
extern t_stat fp15 (int32 ir);
extern int32 clk_task_upd (t_bool clr);
#else
#define INDEX(i,x)
#endif
extern int32 clk (int32 dev, int32 pulse, int32 AC);
int32 (*dev_tab[DEV_MAX])(int32 dev, int32 pulse, int32 AC); /* device dispatch */
int32 (*dev_iors[DEV_MAX])(void); /* IORS dispatch */
static const int32 api_ffo[256] = {
8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
static const int32 api_vec[API_HLVL][32] = {
{ ACH_PWRFL }, /* API 0 */
{ ACH_DTA, ACH_MTA, ACH_DRM, ACH_RF, ACH_RP, ACH_RB }, /* API 1 */
{ ACH_PTR, ACH_LPT, ACH_LPT }, /* API 2 */
{ ACH_CLK, ACH_TTI1, ACH_TTO1 } /* API 3 */
};
/* CPU data structures
cpu_dev CPU device descriptor
cpu_unit CPU unit
cpu_reg CPU register list
cpu_mod CPU modifier list
*/
UNIT cpu_unit = {
UDATA (NULL, UNIT_FIX+UNIT_BINK+EAE_DFLT+API_DFLT+PROT_DFLT,
MAXMEMSIZE)
};
REG cpu_reg[] = {
{ ORDATA (PC, PC, ADDRSIZE) },
{ ORDATA (AC, LAC, 18) },
{ FLDATA (L, LAC, 18) },
{ ORDATA (MQ, MQ, 18) },
{ ORDATA (SC, SC, 6) },
{ FLDATA (EAE_AC_SIGN, eae_ac_sign, 18) },
{ ORDATA (SR, SR, 18) },
{ ORDATA (ASW, ASW, ADDRSIZE) },
{ ORDATA (IORS, iors, 18), REG_RO },
{ BRDATA (INT, int_hwre, 8, 32, API_HLVL+1), REG_RO },
{ FLDATA (INT_PEND, int_pend, 0), REG_RO },
{ FLDATA (ION, ion, 0) },
{ ORDATA (ION_DELAY, ion_defer, 2) },
#if defined (PDP7)
{ FLDATA (TRAPM, usmd, 0) },
{ FLDATA (TRAPP, trap_pending, 0) },
{ FLDATA (EXTM, memm, 0) },
{ FLDATA (EXTM_INIT, memm_init, 0) },
{ FLDATA (EMIRP, emir_pending, 0) },
#endif
#if defined (PDP9)
{ FLDATA (APIENB, api_enb, 0) },
{ ORDATA (APIREQ, api_req, 8) },
{ ORDATA (APIACT, api_act, 8) },
{ ORDATA (BR, BR, ADDRSIZE) },
{ FLDATA (USMD, usmd, 0) },
{ FLDATA (USMDBUF, usmd_buf, 0) },
{ FLDATA (USMDDEF, usmd_defer, 0) },
{ FLDATA (NEXM, nexm, 0) },
{ FLDATA (PRVN, prvn, 0) },
{ FLDATA (TRAPP, trap_pending, 0) },
{ FLDATA (EXTM, memm, 0) },
{ FLDATA (EXTM_INIT, memm_init, 0) },
{ FLDATA (EMIRP, emir_pending, 0) },
{ FLDATA (RESTP, rest_pending, 0) },
{ FLDATA (PWRFL, int_hwre[API_PWRFL], INT_V_PWRFL) },
#endif
#if defined (PDP15)
{ FLDATA (ION_INH, ion_inh, 0) },
{ FLDATA (APIENB, api_enb, 0) },
{ ORDATA (APIREQ, api_req, 8) },
{ ORDATA (APIACT, api_act, 8) },
{ ORDATA (XR, XR, 18) },
{ ORDATA (LR, LR, 18) },
{ ORDATA (BR, BR, 18) },
{ ORDATA (RR, RR, 18) },
{ ORDATA (MMR, MMR, 18) },
{ FLDATA (USMD, usmd, 0) },
{ FLDATA (USMDBUF, usmd_buf, 0) },
{ FLDATA (USMDDEF, usmd_defer, 0) },
{ FLDATA (NEXM, nexm, 0) },
{ FLDATA (PRVN, prvn, 0) },
{ FLDATA (TRAPP, trap_pending, 0) },
{ FLDATA (BANKM, memm, 0) },
{ FLDATA (BANKM_INIT, memm_init, 0) },
{ FLDATA (RESTP, rest_pending, 0) },
{ FLDATA (PWRFL, int_hwre[API_PWRFL], INT_V_PWRFL) },
#endif
{ BRDATA (PCQ, pcq, 8, ADDRSIZE, PCQ_SIZE), REG_RO+REG_CIRC },
{ ORDATA (PCQP, pcq_p, 6), REG_HRO },
{ FLDATA (STOP_INST, stop_inst, 0) },
{ DRDATA (XCT_MAX, xct_max, 8), PV_LEFT + REG_NZ },
{ ORDATA (WRU, sim_int_char, 8) },
{ NULL } };
MTAB cpu_mod[] = {
{ UNIT_NOEAE, UNIT_NOEAE, "no EAE", "NOEAE", NULL },
{ UNIT_NOEAE, 0, "EAE", "EAE", NULL },
#if defined (PDP9) || defined (PDP15)
{ UNIT_NOAPI, UNIT_NOAPI, "no API", "NOAPI", NULL },
{ UNIT_NOAPI, 0, "API", "API", NULL },
{ UNIT_PROT+UNIT_RELOC+UNIT_XVM, 0, "no memory protect",
"NOPROTECT", NULL },
{ UNIT_PROT+UNIT_RELOC+UNIT_XVM, UNIT_PROT, "memory protect",
"PROTECT", NULL },
#endif
#if defined (PDP15)
{ UNIT_PROT+UNIT_RELOC+UNIT_XVM, UNIT_PROT+UNIT_RELOC,
"memory relocation", "RELOCATION", NULL },
{ UNIT_PROT+UNIT_RELOC+UNIT_XVM, UNIT_PROT+UNIT_RELOC+UNIT_XVM,
"XVM", "XVM", NULL },
#endif
{ MTAB_XTD|MTAB_VDV, 0, "IDLE", "IDLE", &sim_set_idle, &sim_show_idle },
{ MTAB_XTD|MTAB_VDV, 0, NULL, "NOIDLE", &sim_clr_idle, NULL },
#if defined (PDP4)
{ UNIT_MSIZE, 4096, NULL, "4K", &cpu_set_size },
#endif
{ UNIT_MSIZE, 8192, NULL, "8K", &cpu_set_size },
#if (MAXMEMSIZE > 8192)
{ UNIT_MSIZE, 12288, NULL, "12K", &cpu_set_size },
{ UNIT_MSIZE, 16384, NULL, "16K", &cpu_set_size },
{ UNIT_MSIZE, 20480, NULL, "20K", &cpu_set_size },
{ UNIT_MSIZE, 24576, NULL, "24K", &cpu_set_size },
{ UNIT_MSIZE, 28672, NULL, "28K", &cpu_set_size },
{ UNIT_MSIZE, 32768, NULL, "32K", &cpu_set_size },
#endif
#if (MAXMEMSIZE > 32768)
{ UNIT_MSIZE, 49152, NULL, "48K", &cpu_set_size },
{ UNIT_MSIZE, 65536, NULL, "64K", &cpu_set_size },
{ UNIT_MSIZE, 81920, NULL, "80K", &cpu_set_size },
{ UNIT_MSIZE, 98304, NULL, "96K", &cpu_set_size },
{ UNIT_MSIZE, 114688, NULL, "112K", &cpu_set_size },
{ UNIT_MSIZE, 131072, NULL, "128K", &cpu_set_size },
#endif
{ MTAB_XTD|MTAB_VDV|MTAB_NMO|MTAB_SHP, 0, "HISTORY", "HISTORY",
&cpu_set_hist, &cpu_show_hist },
{ 0 }
};
DEVICE cpu_dev = {
"CPU", &cpu_unit, cpu_reg, cpu_mod,
1, 8, ADDRSIZE, 1, 8, 18,
&cpu_ex, &cpu_dep, &cpu_reset,
NULL, NULL, NULL
};
t_stat sim_instr (void)
{
int32 api_int, api_usmd, skp;
int32 iot_data, device, pulse;
int32 last_IR;
t_stat reason;
if (build_dev_tab ()) /* build, chk tables */
return SCPE_STOP;
PC = PC & AMASK; /* clean variables */
LAC = LAC & LACMASK;
MQ = MQ & DMASK;
reason = 0;
last_IR = -1;
if (cpu_unit.flags & UNIT_NOAPI) /* no API? */
api_enb = api_req = api_act = 0;
api_int = api_eval (&int_pend); /* eval API */
api_usmd = 0; /* not API user cycle */
/* Main instruction fetch/decode loop */
while (reason == 0) { /* loop until halted */
int32 IR, MA, MB, esc, t, xct_count;
int32 link_init, fill;
if (sim_interval <= 0) { /* check clock queue */
/* Make sure all intermediate state is visible in simh registers */
iors = upd_iors (); /* get IORS */
pcq_r->qptr = pcq_p; /* update pc q ptr */
if ((reason = sim_process_event ()))
break;
api_int = api_eval (&int_pend); /* eval API */
}
/* PDP-4 and PDP-7 traps and interrupts
PDP-4 no trap
PDP-7 trap: extend mode forced on, M[0] = PC, PC = 2
PDP-4, PDP-7 programmable interrupts only */
#if defined (PDP4) || defined (PDP7)
#if defined (PDP7)
if (trap_pending) { /* trap pending? */
PCQ_ENTRY; /* save old PC */
MB = Jms_word (1); /* save state */
ion = 0; /* interrupts off */
memm = 1; /* extend on */
emir_pending = trap_pending = 0; /* emir, trap off */
usmd = usmd_buf = 0; /* user mode off */
Write (0, MB, WR); /* save in 0 */
PC = 2; /* fetch next from 2 */
}
#endif
if (int_pend && ion && !ion_defer) { /* interrupt? */
PCQ_ENTRY; /* save old PC */
MB = Jms_word (usmd); /* save state */
ion = 0; /* interrupts off */
memm = 0; /* extend off */
emir_pending = rest_pending = 0; /* emir, restore off */
usmd = usmd_buf = 0; /* user mode off */
Write (0, MB, WR); /* physical write */
PC = 1; /* fetch next from 1 */
}
if (sim_brk_summ && sim_brk_test (PC, SWMASK ('E'))) { /* breakpoint? */
reason = STOP_IBKPT; /* stop simulation */
break;
}
#endif /* end PDP-4/PDP-7 */
/* PDP-9 and PDP-15 traps and interrupts
PDP-9 trap: extend mode ???, M[0/20] = PC, PC = 0/21
PDP-15 trap: bank mode unchanged, M[0/20] = PC, PC = 0/21
PDP-9, PDP-15 API and program interrupts */
#if defined (PDP9) || defined (PDP15)
if (trap_pending) { /* trap pending? */
PCQ_ENTRY; /* save old PC */
MB = Jms_word (1); /* save state */
if (ion) { /* int on? */
ion = 0; /* interrupts off */
MA = 0; /* treat like PI */
#if defined (PDP15)
ion_defer = 2; /* free instruction */
if (!(cpu_unit.flags & UNIT_NOAPI)) { /* API? */
api_act = api_act | API_ML3; /* set lev 3 active */
api_int = api_eval (&int_pend); /* re-evaluate */
}
#endif
}
else MA = 020; /* sortof like CAL */
emir_pending = rest_pending = trap_pending = 0; /* emir,rest,trap off */
usmd = usmd_buf = 0; /* user mode off */
Write (MA, MB, WR); /* physical write */
PC = MA + 1; /* fetch next */
}
if (api_int && !ion_defer) { /* API intr? */
int32 i, lvl = api_int - 1; /* get req level */
if (hst_lnt) /* record */
cpu_intr_hist (HIST_API, lvl);
api_act = api_act | (API_ML0 >> lvl); /* set level active */
if (lvl >= API_HLVL) { /* software req? */
MA = ACH_SWRE + lvl - API_HLVL; /* vec = 40:43 */
api_req = api_req & ~(API_ML0 >> lvl); /* remove request */
}
else {
MA = 0; /* assume fails */
for (i = 0; i < 32; i++) { /* loop hi to lo */
if ((int_hwre[lvl] >> i) & 1) { /* int req set? */
MA = api_vec[lvl][i]; /* get vector */
break; /* and stop */
}
}
}
if (MA == 0) { /* bad channel? */
reason = STOP_API; /* API error */
break;
}
api_int = api_eval (&int_pend); /* no API int */
api_usmd = usmd; /* API user mode cycle */
usmd = usmd_buf = 0; /* user mode off */
emir_pending = rest_pending = 0; /* emir, restore off */
xct_count = 0;
Read (MA, &IR, FE); /* fetch instruction */
goto xct_instr;
}
if (int_pend && ion && !ion_defer && /* int pending, enabled? */
!(api_enb && (api_act & API_MASKPI))) { /* API off or not masking PI? */
PCQ_ENTRY; /* save old PC */
if (hst_lnt) /* record */
cpu_intr_hist (HIST_PI, 0);
MB = Jms_word (usmd); /* save state */
ion = 0; /* interrupts off */
ion_defer = 2; /* free instruction */
#if defined (PDP9) /* PDP-9, */
memm = 0; /* extend off */
#else /* PDP-15 */
if (!(cpu_unit.flags & UNIT_NOAPI)) { /* API? */
api_act = api_act | API_ML3; /* set lev 3 active */
api_int = api_eval (&int_pend); /* re-evaluate */
}
#endif
emir_pending = rest_pending = 0; /* emir, restore off */
usmd = usmd_buf = 0; /* user mode off */
Write (0, MB, WR); /* physical write */
PC = 1; /* fetch next from 1 */
}
if (sim_brk_summ && sim_brk_test (PC, SWMASK ('E'))) { /* breakpoint? */
reason = STOP_IBKPT; /* stop simulation */
break;
}
if (!usmd_defer) /* no IOT? load usmd */
usmd = usmd_buf;
else usmd_defer = 0; /* cancel defer */
#endif /* PDP-9/PDP-15 */
/* Instruction fetch and address decode */
xct_count = 0; /* track nested XCT's */
MA = PC; /* fetch at PC */
if (Read (MA, &IR, FE)) /* fetch instruction */
continue;
PC = Incr_addr (PC); /* increment PC */
xct_instr: /* label for API, XCT */
if (hst_lnt) /* history? */
cpu_inst_hist (MA, IR);
if (ion_defer) /* count down defer */
ion_defer = ion_defer - 1;
if (sim_interval)
sim_interval = sim_interval - 1;
#if defined (PDP15) /* PDP15 */
if (memm) /* bank mode dir addr */
MA = (MA & B_EPCMASK) | (IR & B_DAMASK);
else MA = (MA & P_EPCMASK) | (IR & P_DAMASK); /* page mode dir addr */
#else /* others */
MA = (MA & B_EPCMASK) | (IR & B_DAMASK); /* bank mode only */
#endif
switch ((IR >> 13) & 037) { /* decode IR<0:4> */
/* LAC: opcode 20 */
case 011: /* LAC, indir */
if (Ia (MA, &MA, 0))
break;
case 010: /* LAC, dir */
INDEX (IR, MA);
if (Read (MA, &MB, RD))
break;
LAC = (LAC & LINK) | MB;
break;
/* DAC: opcode 04 */
case 003: /* DAC, indir */
if (Ia (MA, &MA, 0))
break;
case 002: /* DAC, dir */
INDEX (IR, MA);
Write (MA, LAC & DMASK, WR);
break;
/* DZM: opcode 14 */
case 007: /* DZM, indir */
if (Ia (MA, &MA, 0))
break;
case 006: /* DZM, direct */
INDEX (IR, MA);
Write (MA, 0, WR);
break;
/* AND: opcode 50 */
case 025: /* AND, ind */
if (Ia (MA, &MA, 0))
break;
case 024: /* AND, dir */
INDEX (IR, MA);
if (Read (MA, &MB, RD))
break;
LAC = LAC & (MB | LINK);
break;
/* XOR: opcode 24 */
case 013: /* XOR, ind */
if (Ia (MA, &MA, 0))
break;
case 012: /* XOR, dir */
INDEX (IR, MA);
if (Read (MA, &MB, RD))
break;
LAC = LAC ^ MB;
break;
/* ADD: opcode 30 */
case 015: /* ADD, indir */
if (Ia (MA, &MA, 0))
break;
case 014: /* ADD, dir */
INDEX (IR, MA);
if (Read (MA, &MB, RD))
break;
t = (LAC & DMASK) + MB;
if (t > DMASK) /* end around carry */
t = (t + 1) & DMASK;
if (((~LAC ^ MB) & (LAC ^ t)) & SIGN) /* overflow? */
LAC = LINK | t; /* set link */
else LAC = (LAC & LINK) | t;
break;
/* TAD: opcode 34 */
case 017: /* TAD, indir */
if (Ia (MA, &MA, 0))
break;
case 016: /* TAD, dir */
INDEX (IR, MA);
if (Read (MA, &MB, RD))
break;
LAC = (LAC + MB) & LACMASK;
break;
/* ISZ: opcode 44 */
case 023: /* ISZ, indir */
if (Ia (MA, &MA, 0))
break;
case 022: /* ISZ, dir */
INDEX (IR, MA);
if (Read (MA, &MB, RD))
break;
MB = (MB + 1) & DMASK;
if (Write (MA, MB, WR))
break;
if (MB == 0)
PC = Incr_addr (PC);
break;
/* SAD: opcode 54 */
case 027: /* SAD, indir */
if (Ia (MA, &MA, 0))
break;
case 026: /* SAD, dir */
INDEX (IR, MA);
if (Read (MA, &MB, RD))
break;
if ((LAC & DMASK) != MB)
PC = Incr_addr (PC);
break;
/* XCT: opcode 40 */
case 021: /* XCT, indir */
if (Ia (MA, &MA, 0))
break;
case 020: /* XCT, dir */
INDEX (IR, MA);
if ((api_usmd | usmd) && (xct_count != 0)) { /* chained and usmd? */
if (usmd) /* trap if usmd */
prvn = trap_pending = 1;
break; /* nop if api_usmd */
}
if (xct_count >= xct_max) { /* too many XCT's? */
reason = STOP_XCT;
break;
}
xct_count = xct_count + 1; /* count XCT's */
#if defined (PDP9)
ion_defer = 1; /* defer intr */
#endif
if (Read (MA, &IR, FE)) /* fetch inst, mm err? */
break;
goto xct_instr; /* go execute */
/* CAL: opcode 00 - api_usmd records whether usmd = 1 at start of API cycle
On the PDP-4 and PDP-7, CAL (I) is exactly the same as JMS (I) 20
On the PDP-9 and PDP-15, CAL clears user mode
On the PDP-9 and PDP-15 with API, CAL activates level 4
On the PDP-15, CAL goes to absolute 20, regardless of mode */
case 001: case 000: /* CAL */
t = usmd; /* save user mode */
#if defined (PDP15) /* PDP15 */
MA = 020; /* MA = abs 20 */
ion_defer = 1; /* "free instruction" */
#else /* others */
if (memm) /* if ext, abs 20 */
MA = 020;
else MA = (PC & B_EPCMASK) | 020; /* else bank-rel 20 */
#endif
#if defined (PDP9) || defined (PDP15)
usmd = usmd_buf = 0; /* clear user mode */
if ((cpu_unit.flags & UNIT_NOAPI) == 0) { /* if API, act lvl 4 */
#if defined (PDP15) /* PDP15: if 0-3 inactive */
if ((api_act & (API_ML0|API_ML1|API_ML2|API_ML3)) == 0)
#endif
api_act = api_act | API_ML4;
api_int = api_eval (&int_pend);
}
#endif
if (IR & I_IND) { /* indirect? */
if (Ia (MA, &MA, 0))
break;
}
PCQ_ENTRY;
MB = Jms_word (api_usmd | t); /* save state */
Write (MA, MB, WR);
PC = Incr_addr (MA);
break;
/* JMS: opcode 010 - api_usmd records whether usmd = 1 at start of API cycle */
case 005: /* JMS, indir */
if (Ia (MA, &MA, 0))
break;
case 004: /* JMS, dir */
INDEX (IR, MA);
PCQ_ENTRY;
#if defined (PDP15) /* PDP15 */
if (!usmd) /* "free instruction" */
ion_defer = 1;
#endif
MB = Jms_word (api_usmd | usmd); /* save state */
if (Write (MA, MB, WR))
break;
PC = Incr_addr (MA) & AMASK;
break;
/* JMP: opcode 60 */
case 031: /* JMP, indir */
if (Ia (MA, &MA, 1))
break;
INDEX (IR, MA);
PCQ_ENTRY; /* save old PC */
PC = MA & AMASK;
break;
/* JMP direct - check for idle */
case 030: /* JMP, dir */
INDEX (IR, MA);
PCQ_ENTRY; /* save old PC */
if (sim_idle_enab) { /* idling enabled? */
t_bool iof = (ion_inh != 0) || /* IOF if inhibited */
((ion == 0) && (api_enb == 0)); /* or PI and api off */
if (((MA ^ (PC - 2)) & AMASK) == 0) { /* 1) JMP *-1? */
if (iof && (last_IR == OP_KSF) && /* iof, prv KSF, */
!TST_INT (TTI)) /* no TTI flag? */
sim_idle (0, FALSE); /* we're idle */
}
else if (((MA ^ (PC - 1)) & AMASK) == 0) { /* 2) JMP *? */
if (iof) /* iof? inf loop */
reason = STOP_LOOP;
else sim_idle (0, FALSE); /* ion? idle */
}
} /* end idle */
PC = MA & AMASK;
break;
/* OPR: opcode 74 */
case 037: /* OPR, indir */
LAC = (LAC & LINK) | IR; /* LAW */
break;
case 036: /* OPR, dir */
skp = 0; /* assume no skip */
switch ((IR >> 6) & 017) { /* decode IR<8:11> */
case 0: /* nop */
break;
case 1: /* SMA */
if ((LAC & SIGN) != 0)
skp = 1;
break;
case 2: /* SZA */
if ((LAC & DMASK) == 0)
skp = 1;
break;
case 3: /* SZA | SMA */
if (((LAC & DMASK) == 0) || ((LAC & SIGN) != 0))
skp = 1;
break;
case 4: /* SNL */
if (LAC >= LINK)
skp = 1;
break;
case 5: /* SNL | SMA */
if (LAC >= SIGN)
skp = 1;
break;
case 6: /* SNL | SZA */
if ((LAC >= LINK) || (LAC == 0))
skp = 1;
break;
case 7: /* SNL | SZA | SMA */
if ((LAC >= SIGN) || (LAC == 0))
skp = 1;
break;
case 010: /* SKP */
skp = 1;
break;
case 011: /* SPA */
if ((LAC & SIGN) == 0)
skp = 1;
break;
case 012: /* SNA */
if ((LAC & DMASK) != 0)
skp = 1;
break;
case 013: /* SNA & SPA */
if (((LAC & DMASK) != 0) && ((LAC & SIGN) == 0))
skp = 1;
break;
case 014: /* SZL */
if (LAC < LINK)
skp = 1;
break;
case 015: /* SZL & SPA */
if (LAC < SIGN)
skp = 1;
break;
case 016: /* SZL & SNA */
if ((LAC < LINK) && (LAC != 0))
skp = 1;
break;
case 017: /* SZL & SNA & SPA */
if ((LAC < SIGN) && (LAC != 0))
skp = 1;
break;
} /* end switch skips */
switch (((IR >> 9) & 014) | (IR & 03)) { /* IR<5:6,16:17> */
case 0: /* NOP */
break;
case 1: /* CMA */
LAC = LAC ^ DMASK;
break;
case 2: /* CML */
LAC = LAC ^ LINK;
break;
case 3: /* CML CMA */
LAC = LAC ^ LACMASK;
break;
case 4: /* CLL */
LAC = LAC & DMASK;
break;
case 5: /* CLL CMA */
LAC = (LAC & DMASK) ^ DMASK;
break;
case 6: /* CLL CML = STL */
LAC = LAC | LINK;
break;
case 7: /* CLL CML CMA */
LAC = (LAC | LINK) ^ DMASK;
break;
case 010: /* CLA */
LAC = LAC & LINK;
break;
case 011: /* CLA CMA = STA */
LAC = LAC | DMASK;
break;
case 012: /* CLA CML */
LAC = (LAC & LINK) ^ LINK;
break;
case 013: /* CLA CML CMA */
LAC = (LAC | DMASK) ^ LINK;
break;
case 014: /* CLA CLL */
LAC = 0;
break;
case 015: /* CLA CLL CMA */
LAC = DMASK;
break;
case 016: /* CLA CLL CML */
LAC = LINK;
break;
case 017: /* CLA CLL CML CMA */
LAC = LACMASK;
break;
} /* end decode */
if (IR & 0000004) { /* OAS */
#if defined (PDP9) || defined (PDP15)
if (usmd) /* trap if usmd */
prvn = trap_pending = 1;
else if (!api_usmd) /* nop if api_usmd */
#endif
LAC = LAC | SR;
}
switch (((IR >> 8) & 04) | ((IR >> 3) & 03)) { /* decode IR<7,13:14> */
case 1: /* RAL */
LAC = ((LAC << 1) | (LAC >> 18)) & LACMASK;
break;
case 2: /* RAR */
LAC = ((LAC >> 1) | (LAC << 18)) & LACMASK;
break;
case 3: /* RAL RAR */
#if defined (PDP15) /* PDP-15 */
LAC = (LAC + 1) & LACMASK; /* IAC */
#else /* PDP-4,-7,-9 */
reason = stop_inst; /* undefined */
#endif
break;
case 5: /* RTL */
LAC = ((LAC << 2) | (LAC >> 17)) & LACMASK;
break;
case 6: /* RTR */
LAC = ((LAC >> 2) | (LAC << 17)) & LACMASK;
break;
case 7: /* RTL RTR */
#if defined (PDP15) /* PDP-15 */
LAC = ((LAC >> 9) & 0777) | ((LAC & 0777) << 9) |
(LAC & LINK); /* BSW */
#else /* PDP-4,-7,-9 */
reason = stop_inst; /* undefined */
#endif
break;
} /* end switch rotate */
if (IR & 0000040) { /* HLT */
if (usmd) /* trap if usmd */
prvn = trap_pending = 1;
else if (!api_usmd) /* nop if api_usmd */
reason = STOP_HALT;
}
if (skp) /* if skip, inc PC */
PC = Incr_addr (PC);
break; /* end OPR */
/* EAE: opcode 64
The EAE is microprogrammed to execute variable length signed and
unsigned shift, multiply, divide, and normalize. Most commands are
controlled by a six bit step counter (SC). In the hardware, the step
counter is complemented on load and then counted up to zero; timing
guarantees an initial increment, which completes the two's complement
load. In the simulator, the SC is loaded normally and then counted
down to zero; the read SC command compensates. */
case 033: case 032: /* EAE */
if (cpu_unit.flags & UNIT_NOEAE) /* disabled? */
break;
if (IR & 0020000) /* IR<4>? AC0 to L */
LAC = ((LAC << 1) & LINK) | (LAC & DMASK);
if (IR & 0010000) /* IR<5>? clear MQ */
MQ = 0;
if ((IR & 0004000) && (LAC & SIGN)) /* IR<6> and minus? */
eae_ac_sign = LINK; /* set eae_ac_sign */
else eae_ac_sign = 0; /* if not, unsigned */
if (IR & 0002000) /* IR<7>? or AC */
MQ = (MQ | LAC) & DMASK;
else if (eae_ac_sign) /* if not, |AC| */
LAC = LAC ^ DMASK;
if (IR & 0001000) /* IR<8>? clear AC */
LAC = LAC & LINK;
link_init = LAC & LINK; /* link temporary */
fill = link_init? DMASK: 0; /* fill = link */
esc = IR & 077; /* get eff SC */
switch ((IR >> 6) & 07) { /* case on IR<9:11> */
case 0: /* setup */
if (IR & 04) /* IR<15>? ~MQ */
MQ = MQ ^ DMASK;
if (IR & 02) /* IR<16>? or MQ */
LAC = LAC | MQ;
if (IR & 01) /* IR<17>? or SC */
LAC = LAC | ((-SC) & 077);
break;
/* Multiply uses a shift and add algorithm. The PDP-15, unlike prior
implementations, factors IR<6> (signed multiply) into the calculation
of the result sign. */
case 1: /* multiply */
if (Read (PC, &MB, FE)) /* get next word */
break;
PC = Incr_addr (PC); /* increment PC */
if (eae_ac_sign) /* EAE AC sign? ~MQ */
MQ = MQ ^ DMASK;
LAC = LAC & DMASK; /* clear link */
SC = esc; /* init SC */
do { /* loop */
if (MQ & 1) /* MQ<17>? add */
LAC = LAC + MB;
MQ = (MQ >> 1) | ((LAC & 1) << 17);
LAC = LAC >> 1; /* shift AC'MQ right */
SC = (SC - 1) & 077; /* decrement SC */
} while (SC != 0); /* until SC = 0 */
#if defined (PDP15)
if ((IR & 0004000) && (eae_ac_sign ^ link_init)) {
#else
if (eae_ac_sign ^ link_init) { /* result negative? */
#endif
LAC = LAC ^ DMASK;
MQ = MQ ^ DMASK;
}
break;
/* Divide uses a non-restoring divide. Divide uses a subtract and shift
algorithm. The quotient is generated in true form. The PDP-15, unlike
prior implementations, factors IR<6> (signed divide) into the calculation
of the result sign. */
case 3: /* divide */
if (Read (PC, &MB, FE)) /* get next word */
break;
PC = Incr_addr (PC); /* increment PC */
if (eae_ac_sign) /* EAE AC sign? ~MQ */
MQ = MQ ^ DMASK;
if ((LAC & DMASK) >= MB) { /* overflow? */
LAC = (LAC - MB) | LINK; /* set link */
break;
}
LAC = LAC & DMASK; /* clear link */
t = 0; /* init loop */
SC = esc; /* init SC */
do { /* loop */
if (t)
LAC = (LAC + MB) & LACMASK;
else LAC = (LAC - MB) & LACMASK;
t = (LAC >> 18) & 1; /* quotient bit */
if (SC > 1) /* skip if last */
LAC =((LAC << 1) | (MQ >> 17)) & LACMASK;
MQ = ((MQ << 1) | (t ^ 1)) & DMASK; /* shift in quo bit */
SC = (SC - 1) & 077; /* decrement SC */
} while (SC != 0); /* until SC = 0 */
if (t)
LAC = (LAC + MB) & LACMASK;
if (eae_ac_sign) /* sgn rem = sgn divd */
LAC = LAC ^ DMASK;
#if defined (PDP15)
if ((IR & 0004000) && (eae_ac_sign ^ link_init))
#else
if (eae_ac_sign ^ link_init) /* result negative? */
#endif
MQ = MQ ^ DMASK;
break;
/* EAE shifts, whether left or right, fill from the link. If the
operand sign has been copied to the link, this provides correct
sign extension for one's complement numbers. */
case 4: /* normalize */
#if defined (PDP15)
if (!usmd) /* free instructions */
ion_defer = 2;
#endif
for (SC = esc; ((LAC & SIGN) == ((LAC << 1) & SIGN)); ) {
LAC = (LAC << 1) | ((MQ >> 17) & 1);
MQ = (MQ << 1) | (link_init >> 18);
SC = (SC - 1) & 077;
if (SC == 0)
break;
}
LAC = link_init | (LAC & DMASK); /* trim AC, restore L */
MQ = MQ & DMASK; /* trim MQ */
SC = SC & 077; /* trim SC */
break;
case 5: /* long right shift */
if (esc < 18) {
MQ = ((LAC << (18 - esc)) | (MQ >> esc)) & DMASK;
LAC = ((fill << (18 - esc)) | (LAC >> esc)) & LACMASK;
}
else {
if (esc < 36)
MQ = ((fill << (36 - esc)) | (LAC >> (esc - 18))) & DMASK;
else MQ = fill;
LAC = link_init | fill;
}
SC = 0; /* clear step count */
break;
case 6: /* long left shift */
if (esc < 18) {
LAC = link_init | (((LAC << esc) | (MQ >> (18 - esc))) & DMASK);
MQ = ((MQ << esc) | (fill >> (18 - esc))) & DMASK;
}
else {
if (esc < 36)
LAC = link_init | (((MQ << (esc - 18)) | (fill >> (36 - esc))) & DMASK);
else LAC = link_init | fill;
MQ = fill;
}
SC = 0; /* clear step count */
break;
case 7: /* AC left shift */
if (esc < 18)
LAC = link_init | (((LAC << esc) | (fill >> (18 - esc))) & DMASK);
else LAC = link_init | fill;
SC = 0; /* clear step count */
break;
} /* end switch IR */
break; /* end case EAE */
/* PDP-15 index operates: opcode 72 */
case 035: /* index operates */
#if defined (PDP15)
t = (IR & 0400)? (IR | 0777000): (IR & 0377); /* sext immediate */
switch ((IR >> 9) & 017) { /* case on IR<5:8> */
case 001: /* PAX */
XR = LAC & DMASK;
break;
case 002: /* PAL */
LR = LAC & DMASK;
break;
case 003: /* AAC */
LAC = (LAC & LINK) | ((LAC + t) & DMASK);
break;
case 004: /* PXA */
LAC = (LAC & LINK) | XR;
break;
case 005: /* AXS */
XR = (XR + t) & DMASK;
if (SEXT (XR) >= SEXT (LR))
PC = Incr_addr (PC);
break;
case 006: /* PXL */
LR = XR;
break;
case 010: /* PLA */
LAC = (LAC & LINK) | LR;
break;
case 011: /* PLX */
XR = LR;
break;
case 014: /* CLAC */
LAC = LAC & LINK;
break;
case 015: /* CLX */
XR = 0;
break;
case 016: /* CLLR */
LR = 0;
break;
case 017: /* AXR */
XR = (XR + t) & DMASK;
break;
} /* end switch IR */
break; /* end case */
#endif
/* IOT: opcode 70
The 18b PDP's have different definitions of various control IOT's.
IOT PDP-4 PDP-7 PDP-9 PDP-15
700002 IOF IOF IOF IOF
700022 undefined undefined undefined ORMM (XVM)
700042 ION ION ION ION
700024 undefined undefined undefined LDMM (XVM)
700062 undefined ITON undefined undefined
701701 undefined undefined MPSK MPSK
701741 undefined undefined MPSNE MPSNE
701702 undefined undefined MPCV MPCV
701722 undefined undefined undefined MPRC (XVM)
701742 undefined undefined MPEU MPEU
701704 undefined undefined MPLD MPLD
701724 undefined undefined undefined MPLR (KT15, XVM)
701744 undefined undefined MPCNE MPCNE
701764 undefined undefined undefined IPFH (XVM)
703201 undefined undefined PFSF PFSF
703301 undefined TTS TTS TTS
703341 undefined SKP7 SKP7 SPCO
703302 undefined CAF CAF CAF
703304 undefined undefined DBK DBK
703344 undefined undefined DBR DBR
705501 undefined undefined SPI SPI
705521 undefined undefined undefined ENB
705502 undefined undefined RPL RPL
705522 undefined undefined undefined INH
705504 undefined undefined ISA ISA
707701 undefined SEM SEM undefined
707741 undefined undefined undefined SKP15
707761 undefined undefined undefined SBA
707702 undefined EEM EEM undefined
707742 undefined EMIR EMIR RES
707762 undefined undefined undefined DBA
707704 undefined LEM LEM undefined
707764 undefined undefined undefined EBA */
case 034: /* IOT */
#if defined (PDP15)
if (IR & 0010000) { /* floating point? */
reason = fp15 (IR); /* process */
break;
}
#endif
if ((api_usmd | usmd) && /* user, not XVM UIOT? */
(!XVM || !(MMR & MM_UIOT))) {
if (usmd) /* trap if user */
prvn = trap_pending = 1;
break; /* nop if api_usmd */
}
device = (IR >> 6) & 077; /* device = IR<6:11> */
pulse = IR & 067; /* pulse = IR<12:17> */
if (IR & 0000010) /* clear AC? */
LAC = LAC & LINK;
iot_data = LAC & DMASK; /* AC unchanged */
/* PDP-4 system IOT's */
#if defined (PDP4)
switch (device) { /* decode IR<6:11> */
case 0: /* CPU and clock */
if (pulse == 002) /* IOF */
ion = 0;
else if (pulse == 042) /* ION */
ion = ion_defer = 1;
else iot_data = clk (device, pulse, iot_data);
break;
#endif
/* PDP-7 system IOT's */
#if defined (PDP7)
switch (device) { /* decode IR<6:11> */
case 0: /* CPU and clock */
if (pulse == 002) /* IOF */
ion = 0;
else if (pulse == 042) /* ION */
ion = ion_defer = 1;
else if (pulse == 062) /* ITON */
usmd = usmd_buf = ion = ion_defer = 1;
else iot_data = clk (device, pulse, iot_data);
break;
case 033: /* CPU control */
if ((pulse == 001) || (pulse == 041))
PC = Incr_addr (PC);
else if (pulse == 002) /* CAF - skip CPU */
reset_all (1);
break;
case 077: /* extended memory */
if ((pulse == 001) && memm)
PC = Incr_addr (PC);
else if (pulse == 002) /* EEM */
memm = 1;
else if (pulse == 042) /* EMIR */
memm = emir_pending = 1; /* ext on, restore */
else if (pulse == 004) /* LEM */
memm = 0;
break;
#endif
/* PDP-9 system IOT's */
#if defined (PDP9)
ion_defer = 1; /* delay interrupts */
usmd_defer = 1; /* defer load user */
switch (device) { /* decode IR<6:11> */
case 000: /* CPU and clock */
if (pulse == 002) /* IOF */
ion = 0;
else if (pulse == 042) /* ION */
ion = ion_defer = 1;
else iot_data = clk (device, pulse, iot_data);
break;
case 017: /* mem protection */
if (PROT) { /* enabled? */
if ((pulse == 001) && prvn) /* MPSK */
PC = Incr_addr (PC);
else if ((pulse == 041) && nexm) /* MPSNE */
PC = Incr_addr (PC);
else if (pulse == 002) /* MPCV */
prvn = 0;
else if (pulse == 042) /* MPEU */
usmd_buf = 1;
else if (pulse == 004) /* MPLD */
BR = LAC & BRMASK;
else if (pulse == 044) /* MPCNE */
nexm = 0;
}
else reason = stop_inst;
break;
case 032: /* power fail */
if ((pulse == 001) && (TST_INT (PWRFL)))
PC = Incr_addr (PC);
break;
case 033: /* CPU control */
if ((pulse == 001) || (pulse == 041))
PC = Incr_addr (PC);
else if (pulse == 002) { /* CAF */
reset_all (1); /* reset all exc CPU */
cpu_caf (); /* CAF to CPU */
}
else if (pulse == 044) /* DBR */
rest_pending = 1;
if (((cpu_unit.flags & UNIT_NOAPI) == 0) && (pulse & 004)) {
int32 t = api_ffo[api_act & 0377];
api_act = api_act & ~(API_ML0 >> t);
}
break;
case 055: /* API control */
if (cpu_unit.flags & UNIT_NOAPI)
reason = stop_inst;
else if (pulse == 001) { /* SPI */
if (((LAC & SIGN) && api_enb) ||
((LAC & 0377) > api_act))
iot_data = iot_data | IOT_SKP;
}
else if (pulse == 002) { /* RPL */
iot_data = iot_data | (api_enb << 17) |
(api_req << 8) | api_act;
}
else if (pulse == 004) { /* ISA */
api_enb = (iot_data & SIGN)? 1: 0;
api_req = api_req | ((LAC >> 8) & 017);
api_act = api_act | (LAC & 0377);
}
break;
case 077: /* extended memory */
if ((pulse == 001) && memm)
PC = Incr_addr (PC);
else if (pulse == 002) /* EEM */
memm = 1;
else if (pulse == 042) /* EMIR */
memm = emir_pending = 1; /* ext on, restore */
else if (pulse == 004) /* LEM */
memm = 0;
break;
#endif
/* PDP-15 system IOT's - includes "re-entrancy ECO" ENB/INH as standard */
#if defined (PDP15)
ion_defer = 1; /* delay interrupts */
usmd_defer = 1; /* defer load user */
switch (device) { /* decode IR<6:11> */
case 000: /* CPU and clock */
if (pulse == 002) /* IOF */
ion = 0;
else if (pulse == 042) /* ION */
ion = ion_defer = 1;
else if (XVM && (pulse == 022)) /* ORMM/RDMM */
iot_data = MMR;
else if (XVM && (pulse == 024)) /* LDMM */
MMR = iot_data;
else iot_data = clk (device, pulse, iot_data);
break;
case 017: /* mem protection */
if (PROT) { /* enabled? */
t = XVM? BRMASK_XVM: BRMASK;
if ((pulse == 001) && prvn) /* MPSK */
PC = Incr_addr (PC);
else if ((pulse == 041) && nexm) /* MPSNE */
PC = Incr_addr (PC);
else if (pulse == 002) /* MPCV */
prvn = 0;
else if (pulse == 042) /* MPEU */
usmd_buf = 1;
else if (XVM && (pulse == 062)) /* RDCLK */
iot_data = clk_task_upd (TRUE);
else if (pulse == 004) /* MPLD */
BR = LAC & t;
else if (RELOC && (pulse == 024)) /* MPLR */
RR = LAC & t;
else if (pulse == 044) /* MPCNE */
nexm = 0;
}
else reason = stop_inst;
break;
case 032: /* power fail */
if ((pulse == 001) && (TST_INT (PWRFL)))
PC = Incr_addr (PC);
break;
case 033: /* CPU control */
if ((pulse == 001) || (pulse == 041))
PC = Incr_addr (PC);
else if (pulse == 002) { /* CAF */
reset_all (2); /* reset all exc CPU, FP15 */
cpu_caf (); /* CAF to CPU */
}
else if (pulse == 044) /* DBR */
rest_pending = 1;
if (((cpu_unit.flags & UNIT_NOAPI) == 0) && (pulse & 004)) {
int32 t = api_ffo[api_act & 0377];
api_act = api_act & ~(API_ML0 >> t);
}
break;
case 055: /* API control */
if (cpu_unit.flags & UNIT_NOAPI)
reason = stop_inst;
else if (pulse == 001) { /* SPI */
if (((LAC & SIGN) && api_enb) ||
((LAC & 0377) > api_act))
iot_data = iot_data | IOT_SKP;
}
else if (pulse == 002) { /* RPL */
iot_data = iot_data | (api_enb << 17) |
(api_req << 8) | api_act;
}
else if (pulse == 004) { /* ISA */
api_enb = (iot_data & SIGN)? 1: 0;
api_req = api_req | ((LAC >> 8) & 017);
api_act = api_act | (LAC & 0377);
}
else if (pulse == 021) /* ENB */
ion_inh = 0;
else if (pulse == 022) /* INH */
ion_inh = 1;
break;
case 077: /* bank addressing */
if ((pulse == 041) || ((pulse == 061) && memm))
PC = Incr_addr (PC); /* SKP15, SBA */
else if (pulse == 042) /* RES */
rest_pending = 1;
else if (pulse == 062) /* DBA */
memm = 0;
else if (pulse == 064) /* EBA */
memm = 1;
break;
#endif
/* IOT, continued */
default: /* devices */
if (dev_tab[device]) /* defined? */
iot_data = dev_tab[device] (device, pulse, iot_data);
else reason = stop_inst; /* stop on flag */
break;
} /* end switch device */
LAC = LAC | (iot_data & DMASK);
if (iot_data & IOT_SKP)
PC = Incr_addr (PC);
if (iot_data >= IOT_REASON)
reason = iot_data >> IOT_V_REASON;
api_int = api_eval (&int_pend); /* eval API */
break; /* end case IOT */
} /* end switch opcode */
api_usmd = 0; /* API cycle over */
last_IR = IR; /* save IR for next */
} /* end while */
/* Simulation halted */
iors = upd_iors (); /* get IORS */
pcq_r->qptr = pcq_p; /* update pc q ptr */
return reason;
}
/* Evaluate API */
int32 api_eval (int32 *pend)
{
int32 i, hi;
*pend = 0; /* assume no intr */
#if defined (PDP15) /* PDP15 only */
if (ion_inh) /* inhibited? */
return 0;
#endif
for (i = 0; i < API_HLVL+1; i++) { /* any intr? */
if (int_hwre[i])
*pend = 1;
}
if (api_enb == 0) /* off? no req */
return 0;
api_req = api_req & ~(API_ML0|API_ML1|API_ML2|API_ML3); /* clr req<0:3> */
for (i = 0; i < API_HLVL; i++) { /* loop thru levels */
if (int_hwre[i]) /* req on level? */
api_req = api_req | (API_ML0 >> i); /* set api req */
}
hi = api_ffo[api_req & 0377]; /* find hi req */
if (hi < api_ffo[api_act & 0377])
return (hi + 1);
return 0;
}
/* Process IORS instruction */
int32 upd_iors (void)
{
int32 d, p;
d = (ion? IOS_ION: 0); /* ION */
for (p = 0; dev_iors[p] != NULL; p++) /* loop thru table */
d = d | dev_iors[p](); /* OR in results */
return d;
}
#if defined (PDP4) || defined (PDP7)
/* Read, write, indirect, increment routines
On the PDP-4 and PDP-7,
There are autoincrement locations in every field. If a field
does not exist, it is impossible to generate an
autoincrement reference (all instructions are CAL).
Indirect addressing range is determined by extend mode.
JMP I with EMIR pending can only clear extend
There is no memory protection, nxm reads zero and ignores writes. */
t_stat Read (int32 ma, int32 *dat, int32 cyc)
{
ma = ma & AMASK;
if (MEM_ADDR_OK (ma))
*dat = M[ma] & DMASK;
else *dat = 0;
return MM_OK;
}
t_stat Write (int32 ma, int32 dat, int32 cyc)
{
ma = ma & AMASK;
if (MEM_ADDR_OK (ma))
M[ma] = dat & DMASK;
return MM_OK;
}
t_stat Ia (int32 ma, int32 *ea, t_bool jmp)
{
int32 t;
t_stat sta = MM_OK;
if ((ma & B_DAMASK & ~07) == 010) { /* autoindex? */
Read (ma, &t, DF); /* add 1 before use */
t = (t + 1) & DMASK;
sta = Write (ma, t, DF);
}
else sta = Read (ma, &t, DF); /* fetch indirect */
if (jmp) { /* jmp i? */
if (emir_pending && (((t >> 16) & 1) == 0))
memm = 0;
emir_pending = rest_pending = 0;
}
if (memm) /* extend? 15b ia */
*ea = t & IAMASK;
else *ea = (ma & B_EPCMASK) | (t & B_DAMASK); /* bank-rel ia */
return sta;
}
int32 Incr_addr (int32 ma)
{
return ((ma & B_EPCMASK) | ((ma + 1) & B_DAMASK));
}
int32 Jms_word (int32 t)
{
return (((LAC & LINK) >> 1) | ((memm & 1) << 16) |
((t & 1) << 15) | (PC & IAMASK));
}
#endif
#if defined (PDP9)
/* Read, write, indirect, increment routines
On the PDP-9,
The autoincrement registers are in field zero only. Regardless
of extend mode, indirect addressing through 00010-00017
will access absolute locations 00010-00017.
Indirect addressing range is determined by extend mode. If
extend mode is off, and autoincrementing is used, the
resolved address is in bank 0 (KG09B maintenance manual).
JMP I with EMIR pending can only clear extend
JMP I with DBK pending restores L, user mode, extend mode
Memory protection is implemented for foreground/background operation. */
t_stat Read (int32 ma, int32 *dat, int32 cyc)
{
ma = ma & AMASK;
if (usmd) { /* user mode? */
if (!MEM_ADDR_OK (ma)) { /* nxm? */
nexm = prvn = trap_pending = 1; /* set flags, trap */
*dat = 0;
return MM_ERR;
}
if ((cyc != DF) && (ma < BR)) { /* boundary viol? */
prvn = trap_pending = 1; /* set flag, trap */
*dat = 0;
return MM_ERR;
}
}
if (MEM_ADDR_OK (ma)) /* valid mem? ok */
*dat = M[ma] & DMASK;
else {
*dat = 0; /* set flag, no trap */
nexm = 1;
}
return MM_OK;
}
t_stat Write (int32 ma, int32 dat, int32 cyc)
{
ma = ma & AMASK;
if (usmd) {
if (!MEM_ADDR_OK (ma)) { /* nxm? */
nexm = prvn = trap_pending = 1; /* set flags, trap */
return MM_ERR;
}
if ((cyc != DF) && (ma < BR)) { /* boundary viol? */
prvn = trap_pending = 1; /* set flag, trap */
return MM_ERR;
}
}
if (MEM_ADDR_OK (ma)) /* valid mem? ok */
M[ma] = dat & DMASK;
else nexm = 1; /* set flag, no trap */
return MM_OK;
}
t_stat Ia (int32 ma, int32 *ea, t_bool jmp)
{
int32 t;
t_stat sta = MM_OK;
if ((ma & B_DAMASK & ~07) == 010) { /* autoindex? */
ma = ma & 017; /* always in bank 0 */
Read (ma, &t, DF); /* +1 before use */
t = (t + 1) & DMASK;
sta = Write (ma, t, DF);
}
else sta = Read (ma, &t, DF);
if (jmp) { /* jmp i? */
if (emir_pending && (((t >> 16) & 1) == 0))
memm = 0;
if (rest_pending) { /* restore pending? */
LAC = ((t << 1) & LINK) | (LAC & DMASK); /* restore L */
memm = (t >> 16) & 1; /* restore extend */
usmd = usmd_buf = (t >> 15) & 1; /* restore user */
}
emir_pending = rest_pending = 0;
}
if (memm) /* extend? 15b ia */
*ea = t & IAMASK;
else *ea = (ma & B_EPCMASK) | (t & B_DAMASK); /* bank-rel ia */
return sta;
}
int32 Incr_addr (int32 ma)
{
return ((ma & B_EPCMASK) | ((ma + 1) & B_DAMASK));
}
int32 Jms_word (int32 t)
{
return (((LAC & LINK) >> 1) | ((memm & 1) << 16) |
((t & 1) << 15) | (PC & IAMASK));
}
#endif
#if defined (PDP15)
/* Read, write, indirect, increment routines
On the PDP-15,
The autoincrement registers are in page zero only. Regardless
of bank mode, indirect addressing through 00010-00017
will access absolute locations 00010-00017.
Indirect addressing range is determined by autoincrementing.
Any indirect can trigger a restore.
Memory protection is implemented for foreground/background operation.
Read and write mask addresses to 17b except for XVM systems */
t_stat Read (int32 ma, int32 *dat, int32 cyc)
{
int32 pa;
if (usmd) { /* user mode? */
if (XVM) /* XVM relocation? */
pa = RelocXVM (ma, REL_R);
else if (RELOC) /* PDP-15 relocation? */
pa = Reloc15 (ma, REL_R);
else pa = Prot15 (ma, cyc == FE); /* PDP-15 prot, fetch only */
if (pa < 0) { /* error? */
*dat = 0;
return MM_ERR;
}
}
else pa = ma & AMASK; /* no prot or reloc */
if (MEM_ADDR_OK (pa)) /* valid mem? ok */
*dat = M[pa] & DMASK;
else {
nexm = 1; /* set flag, no trap */
*dat = 0;
}
return MM_OK;
}
t_stat Write (int32 ma, int32 dat, int32 cyc)
{
int32 pa;
if (usmd) { /* user mode? */
if (XVM) /* XVM relocation? */
pa = RelocXVM (ma, REL_W);
else if (RELOC) /* PDP-15 relocation? */
pa = Reloc15 (ma, REL_W);
else pa = Prot15 (ma, cyc != DF); /* PDP-15 prot, !defer */
if (pa < 0) /* error? */
return MM_ERR;
}
else pa = ma & AMASK; /* no prot or reloc */
if (MEM_ADDR_OK (pa)) /* valid mem? ok */
M[pa] = dat & DMASK;
else nexm = 1; /* set flag, no trap */
return MM_OK;
}
/* XVM will do 18b defers if user_mode and G_Mode != 0 */
t_stat Ia (int32 ma, int32 *ea, t_bool jmp)
{
int32 gmode, t;
int32 damask = memm? B_DAMASK: P_DAMASK;
static const int32 g_mask[4] = { MM_G_W0, MM_G_W1, MM_G_W2, MM_G_W3 };
t_stat sta = MM_OK;
if ((ma & damask & ~07) == 010) { /* autoincrement? */
ma = ma & 017; /* always in bank 0 */
Read (ma, &t, DF); /* +1 before use */
t = (t + 1) & DMASK;
sta = Write (ma, t, DF);
}
else sta = Read (ma, &t, DF);
if (rest_pending) { /* restore pending? */
LAC = ((t << 1) & LINK) | (LAC & DMASK); /* restore L */
memm = (t >> 16) & 1; /* restore bank */
usmd = usmd_buf = (t >> 15) & 1; /* restore user */
emir_pending = rest_pending = 0;
}
gmode = MM_GETGM (MMR); /* get G_mode */
if (usmd && XVM && gmode) /* XVM user mode? */
*ea = t & g_mask[gmode]; /* mask ia to size */
else if ((ma & damask & ~07) == 010) /* autoindex? */
*ea = t & DMASK;
else *ea = (PC & BLKMASK) | (t & IAMASK); /* within 32K */
return sta;
}
int32 Incr_addr (int32 ma)
{
if (memm)
return ((ma & B_EPCMASK) | ((ma + 1) & B_DAMASK));
return ((ma & P_EPCMASK) | ((ma + 1) & P_DAMASK));
}
/* XVM will store all 18b of PC if user mode and G_mode != 0 */
int32 Jms_word (int32 t)
{
if (usmd && XVM && (MMR & MM_GM))
return PC;
return (((LAC & LINK) >> 1) | ((memm & 1) << 16) |
((t & 1) << 15) | (PC & IAMASK));
}
/* PDP-15 protection (KM15 option) */
int32 Prot15 (int32 ma, t_bool bndchk)
{
ma = ma & AMASK; /* 17b addressing */
if (!MEM_ADDR_OK (ma)) { /* nxm? */
nexm = prvn = trap_pending = 1; /* set flags, trap */
return -1;
}
if (bndchk && (ma < BR)) { /* boundary viol? */
prvn = trap_pending = 1; /* set flag, trap */
return -1;
}
return ma; /* no relocation */
}
/* PDP-15 relocation and protection (KT15 option) */
int32 Reloc15 (int32 ma, int32 rc)
{
int32 pa;
ma = ma & AMASK; /* 17b addressing */
if (ma > (BR | 0377)) { /* boundary viol? */
if (rc != REL_C) /* set flag, trap */
prvn = trap_pending = 1;
return -1;
}
pa = (ma + RR) & AMASK; /* relocate address */
if (!MEM_ADDR_OK (pa)) { /* nxm? */
if (rc != REL_C) /* set flags, trap */
nexm = prvn = trap_pending = 1;
return -1;
}
return pa;
}
/* XVM relocation and protection option */
int32 RelocXVM (int32 ma, int32 rc)
{
int32 pa, gmode, slr;
static const int32 g_base[4] = { MM_G_B0, MM_G_B1, MM_G_B2, MM_G_B3 };
static const int32 slr_lnt[4] = { MM_SLR_L0, MM_SLR_L1, MM_SLR_L2, MM_SLR_L3 };
gmode = MM_GETGM (MMR); /* get G_mode */
slr = MM_GETSLR (MMR); /* get segment length */
if (MMR & MM_RDIS) /* reloc disabled? */
pa = ma;
else if ((MMR & MM_SH) && /* shared enabled and */
(ma >= g_base[gmode]) && /* >= shared base and */
(ma < (g_base[gmode] + slr_lnt[slr]))) { /* < shared end? */
if (ma & 017400) { /* ESAS? */
if ((rc == REL_W) && (MMR & MM_WP)) { /* write and protected? */
prvn = trap_pending = 1; /* set flag, trap */
return -1;
}
pa = (((MMR & MM_SBR_MASK) << 8) + ma) & DMASK; /* ESAS reloc */
}
else pa = RR + (ma & 0377); /* no, ISAS reloc */
}
else {
if (ma > (BR | 0377)) { /* normal reloc, viol? */
if (rc != REL_C) /* set flag, trap */
prvn = trap_pending = 1;
return -1;
}
pa = (RR + ma) & DMASK; /* relocate address */
}
if (!MEM_ADDR_OK (pa)) { /* nxm? */
if (rc != REL_C) /* set flags, trap */
nexm = prvn = trap_pending = 1;
return -1;
}
return pa;
}
#endif
/* Reset routine */
t_stat cpu_reset (DEVICE *dptr)
{
LAC = 0;
MQ = 0;
SC = 0;
eae_ac_sign = 0;
ion = ion_defer = ion_inh = 0;
CLR_INT (PWRFL);
api_enb = api_req = api_act = 0;
BR = 0;
RR = 0;
MMR = 0;
usmd = usmd_buf = usmd_defer = 0;
memm = memm_init;
nexm = prvn = trap_pending = 0;
emir_pending = rest_pending = 0;
pcq_r = find_reg ("PCQ", NULL, dptr);
if (pcq_r)
pcq_r->qptr = 0;
else return SCPE_IERR;
sim_brk_types = sim_brk_dflt = SWMASK ('E');
return SCPE_OK;
}
/* CAF routine (CPU reset isn't called by CAF) */
void cpu_caf (void)
{
api_enb = api_req = api_act = 0; /* reset API system */
nexm = prvn = trap_pending = 0; /* reset MM system */
usmd = usmd_buf = usmd_defer = 0;
MMR = 0;
return;
}
/* Memory examine */
t_stat cpu_ex (t_value *vptr, t_addr addr, UNIT *uptr, int32 sw)
{
#if defined (PDP15)
if (usmd && (sw & SWMASK ('V'))) {
if (XVM)
addr = RelocXVM (addr, REL_C);
else if (RELOC)
addr = Reloc15 (addr, REL_C);
if (((int32) addr) < 0)
return STOP_MME;
}
#endif
if (addr >= MEMSIZE)
return SCPE_NXM;
if (vptr != NULL)
*vptr = M[addr] & DMASK;
return SCPE_OK;
}
/* Memory deposit */
t_stat cpu_dep (t_value val, t_addr addr, UNIT *uptr, int32 sw)
{
#if defined (PDP15)
if (usmd && (sw & SWMASK ('V'))) {
if (XVM)
addr = RelocXVM (addr, REL_C);
else if (RELOC)
addr = Reloc15 (addr, REL_C);
if (((int32) addr) < 0)
return STOP_MME;
}
#endif
if (addr >= MEMSIZE)
return SCPE_NXM;
M[addr] = val & DMASK;
return SCPE_OK;
}
/* Change memory size */
t_stat cpu_set_size (UNIT *uptr, int32 val, char *cptr, void *desc)
{
int32 mc = 0;
uint32 i;
if ((val <= 0) || (val > MAXMEMSIZE) || ((val & 07777) != 0))
return SCPE_ARG;
for (i = val; i < MEMSIZE; i++)
mc = mc | M[i];
if ((mc != 0) && (!get_yn ("Really truncate memory [N]?", FALSE)))
return SCPE_OK;
MEMSIZE = val;
for (i = MEMSIZE; i < MAXMEMSIZE; i++)
M[i] = 0;
return SCPE_OK;
}
/* Change device number for a device */
t_stat set_devno (UNIT *uptr, int32 val, char *cptr, void *desc)
{
DEVICE *dptr;
DIB *dibp;
uint32 newdev;
t_stat r;
if (cptr == NULL)
return SCPE_ARG;
if (uptr == NULL)
return SCPE_IERR;
dptr = find_dev_from_unit (uptr);
if (dptr == NULL)
return SCPE_IERR;
dibp = (DIB *) dptr->ctxt;
if (dibp == NULL)
return SCPE_IERR;
newdev = get_uint (cptr, 8, DEV_MAX - 1, &r); /* get new */
if ((r != SCPE_OK) || (newdev == dibp->dev))
return r;
dibp->dev = newdev; /* store */
return SCPE_OK;
}
/* Show device number for a device */
t_stat show_devno (FILE *st, UNIT *uptr, int32 val, void *desc)
{
DEVICE *dptr;
DIB *dibp;
if (uptr == NULL)
return SCPE_IERR;
dptr = find_dev_from_unit (uptr);
if (dptr == NULL)
return SCPE_IERR;
dibp = (DIB *) dptr->ctxt;
if (dibp == NULL)
return SCPE_IERR;
fprintf (st, "devno=%02o", dibp->dev);
if (dibp->num > 1)
fprintf (st, "-%2o", dibp->dev + dibp->num - 1);
return SCPE_OK;
}
/* CPU device handler - should never get here! */
int32 bad_dev (int32 dev, int32 pulse, int32 AC)
{
return (SCPE_IERR << IOT_V_REASON) | AC; /* broken! */
}
/* Build device dispatch table */
t_bool build_dev_tab (void)
{
DEVICE *dptr;
DIB *dibp;
uint32 i, j, p;
static const uint8 std_dev[] =
#if defined (PDP4)
{ 000 };
#elif defined (PDP7)
{ 000, 033, 077 };
#else
{ 000, 017, 033, 055, 077 };
#endif
for (i = 0; i < DEV_MAX; i++) { /* clr tables */
dev_tab[i] = NULL;
dev_iors[i] = NULL;
}
for (i = 0; i < ((uint32) sizeof (std_dev)); i++) /* std entries */
dev_tab[std_dev[i]] = &bad_dev;
for (i = p = 0; (dptr = sim_devices[i]) != NULL; i++) { /* add devices */
dibp = (DIB *) dptr->ctxt; /* get DIB */
if (dibp && !(dptr->flags & DEV_DIS)) { /* enabled? */
if (dibp->iors) /* if IORS, add */
dev_iors[p++] = dibp->iors;
for (j = 0; j < dibp->num; j++) { /* loop thru disp */
if (dibp->dsp[j]) { /* any dispatch? */
if (dev_tab[dibp->dev + j]) { /* already filled? */
sim_printf ("%s device number conflict at %02o\n",
sim_dname (dptr), dibp->dev + j);
return TRUE;
}
dev_tab[dibp->dev + j] = dibp->dsp[j]; /* fill */
} /* end if dsp */
} /* end for j */
} /* end if enb */
} /* end for i */
return FALSE;
}
/* Set history */
t_stat cpu_set_hist (UNIT *uptr, int32 val, char *cptr, void *desc)
{
int32 i, lnt;
t_stat r;
if (cptr == NULL) {
for (i = 0; i < hst_lnt; i++)
hst[i].pc = 0;
hst_p = 0;
return SCPE_OK;
}
lnt = (int32) get_uint (cptr, 10, HIST_MAX, &r);
if ((r != SCPE_OK) || (lnt && (lnt < HIST_MIN)))
return SCPE_ARG;
hst_p = 0;
if (hst_lnt) {
free (hst);
hst_lnt = 0;
hst = NULL;
}
if (lnt) {
hst = (InstHistory *) calloc (lnt, sizeof (InstHistory));
if (hst == NULL)
return SCPE_MEM;
hst_lnt = lnt;
}
return SCPE_OK;
}
/* Show history */
t_stat cpu_show_hist (FILE *st, UNIT *uptr, int32 val, void *desc)
{
int32 l, j, k, di, lnt;
char *cptr = (char *) desc;
t_value sim_eval[2];
t_stat r;
InstHistory *h;
if (hst_lnt == 0) /* enabled? */
return SCPE_NOFNC;
if (cptr) {
lnt = (int32) get_uint (cptr, 10, hst_lnt, &r);
if ((r != SCPE_OK) || (lnt == 0))
return SCPE_ARG;
}
else lnt = hst_lnt;
di = hst_p - lnt; /* work forward */
if (di < 0)
di = di + hst_lnt;
fprintf (st, "PC L AC MQ IR\n\n");
for (k = 0; k < lnt; k++) { /* print specified */
h = &hst[(di++) % hst_lnt]; /* entry pointer */
if (h->pc & HIST_PC) { /* instruction? */
l = (h->lac >> 18) & 1; /* link */
fprintf (st, "%06o %o %06o %06o ", h->pc & AMASK, l, h->lac & DMASK, h->mq);
sim_eval[0] = h->ir;
sim_eval[1] = h->ir1;
if ((fprint_sym (st, h->pc & AMASK, sim_eval, &cpu_unit, SWMASK ('M'))) > 0)
fprintf (st, "(undefined) %06o", h->ir);
} /* end else instruction */
else if (h->pc & (HIST_API | HIST_PI)) { /* interrupt event? */
if (h->pc & HIST_PI) /* PI? */
fprintf (st, "%06o PI LVL 0-4 =", h->pc & AMASK);
else fprintf (st, "%06o API %d LVL 0-4 =", h->pc & AMASK, h->mq);
for (j = API_HLVL; j >= 0; j--)
fprintf (st, " %02o", (h->ir >> (j * HIST_V_LVL)) & HIST_M_LVL);
}
else continue; /* invalid */
fputc ('\n', st); /* end line */
} /* end for */
return SCPE_OK;
}
/* Record events in history table */
void cpu_inst_hist (int32 addr, int32 inst)
{
t_value word = 0;
hst[hst_p].pc = addr | HIST_PC;
hst[hst_p].ir = inst;
if (cpu_ex (&word, (addr + 1) & AMASK, &cpu_unit, SWMASK ('V')))
hst[hst_p].ir1 = 0;
else hst[hst_p].ir1 = word;
hst[hst_p].lac = LAC;
hst[hst_p].mq = MQ;
hst_p = (hst_p + 1);
if (hst_p >= hst_lnt)
hst_p = 0;
return;
}
void cpu_intr_hist (int32 flag, int32 lvl)
{
int32 j;
hst[hst_p].pc = PC | flag;
hst[hst_p].ir = 0;
for (j = 0; j < API_HLVL+1; j++)
hst[hst_p].ir = (hst[hst_p].ir << HIST_V_LVL) | (int_hwre[j] & HIST_M_LVL);
hst[hst_p].ir1 = 0;
hst[hst_p].lac = 0;
hst[hst_p].mq = lvl;
hst_p = (hst_p + 1);
if (hst_p >= hst_lnt)
hst_p = 0;
return;
}