/* hp2100_cpu2.c: HP 2100/1000 FP/DMS/EIG/IOP instructions | |
Copyright (c) 2005-2016, Robert M. Supnik | |
Copyright (c) 2017 J. David Bryan | |
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 THE | |
AUTHOR 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 names of the authors shall not be | |
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CPU2 Floating-point, dynamic mapping, extended, and I/O processor | |
instructions | |
07-Sep-17 JDB Removed unnecessary "uint16" casts | |
10-Jul-17 JDB Renamed the global routine "iogrp" to "cpu_iog" | |
26-Jun-17 JDB Replaced SEXT with SEXT16 | |
22-Mar-17 JDB Corrected comments regarding IR bit 11 selecting A/B | |
25-Jan-17 JDB Set mp_mem_changed whenever MEM registers are changed | |
05-Aug-16 JDB Renamed the P register from "PC" to "PR" | |
24-Dec-14 JDB Added casts for explicit downward conversions | |
09-May-12 JDB Separated assignments from conditional expressions | |
11-Sep-08 JDB Moved microcode function prototypes to hp2100_cpu1.h | |
05-Sep-08 JDB Removed option-present tests (now in UIG dispatchers) | |
05-Aug-08 JDB Updated mp_dms_jmp calling sequence | |
Fixed DJP, SJP, and UJP jump target validation | |
30-Jul-08 JDB RVA/B conditionally updates dms_vr before returning value | |
19-Dec-06 JDB DMS self-test now executes as NOP on 1000-M | |
01-Dec-06 JDB Substitutes FPP for firmware FP if HAVE_INT64 | |
26-Sep-06 JDB Moved from hp2100_cpu1.c to simplify extensions | |
22-Feb-05 JDB Fixed missing MPCK on JRS target | |
21-Jan-05 JDB Reorganized CPU option and operand processing flags | |
Split code along microcode modules | |
15-Jan-05 RMS Cloned from hp2100_cpu.c | |
Primary references: | |
- HP 1000 M/E/F-Series Computers Technical Reference Handbook | |
(5955-0282, Mar-1980) | |
- HP 1000 M/E/F-Series Computers Engineering and Reference Documentation | |
(92851-90001, Mar-1981) | |
- Macro/1000 Reference Manual (92059-90001, Dec-1992) | |
Additional references are listed with the associated firmware | |
implementations, as are the HP option model numbers pertaining to the | |
applicable CPUs. | |
*/ | |
#include "hp2100_defs.h" | |
#include "hp2100_cpu.h" | |
#include "hp2100_cpu1.h" | |
#if !defined (HAVE_INT64) /* int64 support unavailable */ | |
#include "hp2100_fp.h" | |
/* Single-Precision Floating Point Instructions | |
The 2100 and 1000 CPUs share the single-precision (two word) floating-point | |
instruction codes. Floating-point firmware was an option on the 2100 and was | |
standard on the 1000-M and E. The 1000-F had a standard hardware Floating | |
Point Processor that executed these six instructions and added extended- and | |
double-precision floating- point instructions, as well as double-integer | |
instructions (the FPP is simulated separately). | |
Option implementation by CPU was as follows: | |
2114 2115 2116 2100 1000-M 1000-E 1000-F | |
------ ------ ------ ------ ------ ------ ------ | |
N/A N/A N/A 12901A std std N/A | |
The instruction codes for the 2100 and 1000-M/E systems are mapped to | |
routines as follows: | |
Instr. 2100/1000-M/E Description | |
------ ------------- ----------------------------------- | |
105000 FAD Single real add | |
105020 FSB Single real subtract | |
105040 FMP Single real multiply | |
105060 FDV Single real divide | |
105100 FIX Single integer to single real fix | |
105120 FLT Single real to single integer float | |
Bits 3-0 are not decoded by these instructions, so FAD (e.g.) would be | |
executed by any instruction in the range 105000-105017. | |
Implementation note: rather than have two simulators that each executes the | |
single-precision FP instruction set, we compile conditionally, based on the | |
availability of 64-bit integer support in the host compiler. 64-bit integers | |
are required for the FPP, so if they are available, then the FPP is used to | |
handle the six single-precision instructions for the 2100 and M/E-Series, and | |
this function is omitted. If support is unavailable, this function is used | |
instead. | |
Implementation note: the operands to FAD, etc. are floating-point values, so | |
OP_F would normally be used. However, the firmware FP support routines want | |
floating-point operands as 32-bit integer values, so OP_D is used to achieve | |
this. | |
*/ | |
static const OP_PAT op_fp[8] = { | |
OP_D, OP_D, OP_D, OP_D, /* FAD FSB FMP FDV */ | |
OP_N, OP_N, OP_N, OP_N /* FIX FLT --- --- */ | |
}; | |
t_stat cpu_fp (uint32 IR, uint32 intrq) | |
{ | |
t_stat reason = SCPE_OK; | |
OPS op; | |
uint32 entry; | |
entry = (IR >> 4) & 017; /* mask to entry point */ | |
if (op_fp [entry] != OP_N) { | |
reason = cpu_ops (op_fp [entry], op, intrq); /* get instruction operands */ | |
if (reason != SCPE_OK) /* evaluation failed? */ | |
return reason; /* return reason for failure */ | |
} | |
switch (entry) { /* decode IR<7:4> */ | |
case 000: /* FAD 105000 (OP_D) */ | |
O = f_as (op[0].dword, 0); /* add, upd ovflo */ | |
break; | |
case 001: /* FSB 105020 (OP_D) */ | |
O = f_as (op[0].dword, 1); /* sub, upd ovflo */ | |
break; | |
case 002: /* FMP 105040 (OP_D) */ | |
O = f_mul (op[0].dword); /* mul, upd ovflo */ | |
break; | |
case 003: /* FDV 105060 (OP_D) */ | |
O = f_div (op[0].dword); /* div, upd ovflo */ | |
break; | |
case 004: /* FIX 105100 (OP_N) */ | |
O = f_fix (); /* fix, upd ovflo */ | |
break; | |
case 005: /* FLT 105120 (OP_N) */ | |
O = f_flt (); /* float, upd ovflo */ | |
break; | |
default: /* should be impossible */ | |
return SCPE_IERR; | |
} | |
return reason; | |
} | |
#endif /* int64 support unavailable */ | |
/* Dynamic Mapping System | |
The 1000 Dynamic Mapping System (DMS) consisted of the 12731A Memory | |
Expansion Module (MEM) card and 38 instructions to expand the basic 32K | |
logical address space to a 1024K physical space. The MEM provided four maps | |
of 32 mapping registers each: a system map, a user map, and two DCPC maps. | |
DMS worked in conjunction with memory protect to provide a "protected mode" | |
in which memory read and write violations could be trapped, and that | |
inhibited "privileged" instruction execution that attempted to alter the | |
memory mapping. | |
Option implementation by CPU was as follows: | |
2114 2115 2116 2100 1000-M 1000-E 1000-F | |
------ ------ ------ ------ ------ ------ ------ | |
N/A N/A N/A N/A 12976B 13307B std | |
The instruction codes are mapped to routines as follows: | |
Instr. 1000-M 1000-E/F Instr. 1000-M 1000-E/F | |
------ ------ -------- ------ ------ -------- | |
10x700 [xmm] [xmm] 10x720 XMM XMM | |
10x701 [nop] [test] 10x721 XMS XMS | |
10x702 MBI MBI 10x722 XM* XM* | |
10x703 MBF MBF 10x723 [nop] [nop] | |
10x704 MBW MBW 10x724 XL* XL* | |
10x705 MWI MWI 10x725 XS* XS* | |
10x706 MWF MWF 10x726 XC* XC* | |
10x707 MWW MWW 10x727 LF* LF* | |
10x710 SY* SY* 10x730 RS* RS* | |
10x711 US* US* 10x731 RV* RV* | |
10x712 PA* PA* 10x732 DJP DJP | |
10x713 PB* PB* 10x733 DJS DJS | |
10x714 SSM SSM 10x734 SJP SJP | |
10x715 JRS JRS 10x735 SJS SJS | |
10x716 [nop] [nop] 10x736 UJP UJP | |
10x717 [nop] [nop] 10x737 UJS UJS | |
Instructions that use IR bit 11 to select the A or B register are designated | |
with a * above (e.g., 101710 is SYA, and 105710 is SYB). For those that do | |
not use this feature, either the 101xxx or 105xxx code will execute the | |
corresponding instruction, although the 105xxx form is the documented | |
instruction code. | |
Implementation notes: | |
1. Instruction code 10x700 will execute the XMM instruction, although 10x720 | |
is the documented instruction value. | |
2. Instruction code 10x701 will complement the A or B register, as | |
indicated, on 1000-E and F-Series machines. This instruction is a NOP on | |
M-Series machines. | |
3. The DMS privilege violation rules are: | |
- load map and CTL5 set (XMM, XMS, XM*, SY*, US*, PA*, PB*) | |
- load state or fence and UMAP set (JRS, DJP, DJS, SJP, SJS, UJP, UJS, LF*) | |
4. DM (write) violations for the use of the MBI, MWI, MBW, MWW, XSA, and XSB | |
instructions in protected mode are generated by the mem_write routine. | |
5. The protected memory lower bound for the DJP, SJP, UJP, and JRS | |
instructions is 2. | |
*/ | |
static const OP_PAT op_dms[32] = { | |
OP_N, OP_N, OP_N, OP_N, /* [xmm] [test] MBI MBF */ | |
OP_N, OP_N, OP_N, OP_N, /* MBW MWI MWF MWW */ | |
OP_N, OP_N, OP_N, OP_N, /* SYA/B USA/B PAA/B PBA/B */ | |
OP_A, OP_KA, OP_N, OP_N, /* SSM JRS nop nop */ | |
OP_N, OP_N, OP_N, OP_N, /* XMM XMS XMA/B nop */ | |
OP_A, OP_A, OP_A, OP_N, /* XLA/B XSA/B XCA/B LFA/B */ | |
OP_N, OP_N, OP_A, OP_A, /* RSA/B RVA/B DJP DJS */ | |
OP_A, OP_A, OP_A, OP_A /* SJP SJS UJP UJS */ | |
}; | |
t_stat cpu_dms (uint32 IR, uint32 intrq) | |
{ | |
t_stat reason = SCPE_OK; | |
OPS op; | |
uint8 byte; | |
uint32 entry, absel, i, mapi, mapj; | |
HP_WORD t; | |
absel = (IR & I_AB)? 1: 0; /* get A/B select */ | |
entry = IR & 037; /* mask to entry point */ | |
if (op_dms [entry] != OP_N) { | |
reason = cpu_ops (op_dms [entry], op, intrq); /* get instruction operands */ | |
if (reason != SCPE_OK) /* evaluation failed? */ | |
return reason; /* return reason for failure */ | |
} | |
switch (entry) { /* decode IR<3:0> */ | |
/* DMS module 1 */ | |
case 000: /* [undefined] 105700 (OP_N) */ | |
goto XMM; /* decodes as XMM */ | |
case 001: /* [self test] 105701 (OP_N) */ | |
if (UNIT_CPU_MODEL != UNIT_1000_M) /* executes as NOP on 1000-M */ | |
ABREG[absel] = ~ABREG[absel]; /* CMA or CMB */ | |
break; | |
case 002: /* MBI 105702 (OP_N) */ | |
AR = AR & ~1; /* force A, B even */ | |
BR = BR & ~1; | |
while (XR != 0) { /* loop */ | |
byte = ReadB (AR); /* read curr */ | |
WriteBA (BR, byte); /* write alt */ | |
AR = (AR + 1) & DMASK; /* incr ptrs */ | |
BR = (BR + 1) & DMASK; | |
XR = (XR - 1) & DMASK; | |
if (XR && intrq && !(AR & 1)) { /* more, int, even? */ | |
PR = err_PC; /* stop for now */ | |
break; | |
} | |
} | |
break; | |
case 003: /* MBF 105703 (OP_N) */ | |
AR = AR & ~1; /* force A, B even */ | |
BR = BR & ~1; | |
while (XR != 0) { /* loop */ | |
byte = ReadBA (AR); /* read alt */ | |
WriteB (BR, byte); /* write curr */ | |
AR = (AR + 1) & DMASK; /* incr ptrs */ | |
BR = (BR + 1) & DMASK; | |
XR = (XR - 1) & DMASK; | |
if (XR && intrq && !(AR & 1)) { /* more, int, even? */ | |
PR = err_PC; /* stop for now */ | |
break; | |
} | |
} | |
break; | |
case 004: /* MBW 105704 (OP_N) */ | |
AR = AR & ~1; /* force A, B even */ | |
BR = BR & ~1; | |
while (XR != 0) { /* loop */ | |
byte = ReadBA (AR); /* read alt */ | |
WriteBA (BR, byte); /* write alt */ | |
AR = (AR + 1) & DMASK; /* incr ptrs */ | |
BR = (BR + 1) & DMASK; | |
XR = (XR - 1) & DMASK; | |
if (XR && intrq && !(AR & 1)) { /* more, int, even? */ | |
PR = err_PC; /* stop for now */ | |
break; | |
} | |
} | |
break; | |
case 005: /* MWI 105705 (OP_N) */ | |
while (XR != 0) { /* loop */ | |
t = ReadW (AR & VAMASK); /* read curr */ | |
WriteWA (BR & VAMASK, t); /* write alt */ | |
AR = (AR + 1) & DMASK; /* incr ptrs */ | |
BR = (BR + 1) & DMASK; | |
XR = (XR - 1) & DMASK; | |
if (XR && intrq) { /* more and intr? */ | |
PR = err_PC; /* stop for now */ | |
break; | |
} | |
} | |
break; | |
case 006: /* MWF 105706 (OP_N) */ | |
while (XR != 0) { /* loop */ | |
t = ReadWA (AR & VAMASK); /* read alt */ | |
WriteW (BR & VAMASK, t); /* write curr */ | |
AR = (AR + 1) & DMASK; /* incr ptrs */ | |
BR = (BR + 1) & DMASK; | |
XR = (XR - 1) & DMASK; | |
if (XR && intrq) { /* more and intr? */ | |
PR = err_PC; /* stop for now */ | |
break; | |
} | |
} | |
break; | |
case 007: /* MWW 105707 (OP_N) */ | |
while (XR != 0) { /* loop */ | |
t = ReadWA (AR & VAMASK); /* read alt */ | |
WriteWA (BR & VAMASK, t); /* write alt */ | |
AR = (AR + 1) & DMASK; /* incr ptrs */ | |
BR = (BR + 1) & DMASK; | |
XR = (XR - 1) & DMASK; | |
if (XR && intrq) { /* more and intr? */ | |
PR = err_PC; /* stop for now */ | |
break; | |
} | |
} | |
break; | |
case 010: /* SYA, SYB 10x710 (OP_N) */ | |
case 011: /* USA, USB 10x711 (OP_N) */ | |
case 012: /* PAA, PAB 10x712 (OP_N) */ | |
case 013: /* PBA, PBB 10x713 (OP_N) */ | |
mapi = (IR & 03) << VA_N_PAG; /* map base */ | |
if (ABREG[absel] & SIGN) { /* store? */ | |
for (i = 0; i < MAP_LNT; i++) { | |
t = dms_rmap (mapi + i); /* map to memory */ | |
WriteW ((ABREG[absel] + i) & VAMASK, t); | |
} | |
} | |
else { /* load */ | |
dms_viol (err_PC, MVI_PRV); /* priv if PRO */ | |
for (i = 0; i < MAP_LNT; i++) { | |
t = ReadW ((ABREG[absel] + i) & VAMASK); | |
dms_wmap (mapi + i, t); /* mem to map */ | |
} | |
} | |
ABREG[absel] = (ABREG[absel] + MAP_LNT) & DMASK; | |
break; | |
case 014: /* SSM 105714 (OP_A) */ | |
WriteW (op[0].word, dms_upd_sr ()); /* store stat */ | |
break; | |
case 015: /* JRS 105715 (OP_KA) */ | |
if (dms_ump) dms_viol (err_PC, MVI_PRV); /* priv viol if prot */ | |
dms_enb = 0; /* assume off */ | |
dms_ump = SMAP; | |
if (op[0].word & 0100000) { /* set enable? */ | |
dms_enb = 1; | |
if (op[0].word & 0040000) dms_ump = UMAP; /* set/clr usr */ | |
} | |
mp_mem_changed = TRUE; /* set the MP/MEM registers changed flag */ | |
mp_dms_jmp (op[1].word, 2); /* mpck jmp target */ | |
PCQ_ENTRY; /* save old P */ | |
PR = op[1].word; /* jump */ | |
ion_defer = TRUE; /* defer intr */ | |
break; | |
/* DMS module 2 */ | |
case 020: /* XMM 105720 (OP_N) */ | |
XMM: | |
if (XR == 0) break; /* nop? */ | |
while (XR != 0) { /* loop */ | |
if (XR & SIGN) { /* store? */ | |
t = dms_rmap (AR); /* map to mem */ | |
WriteW (BR & VAMASK, t); | |
XR = (XR + 1) & DMASK; | |
} | |
else { /* load */ | |
dms_viol (err_PC, MVI_PRV); /* priv viol if prot */ | |
t = ReadW (BR & VAMASK); /* mem to map */ | |
dms_wmap (AR, t); | |
XR = (XR - 1) & DMASK; | |
} | |
AR = (AR + 1) & DMASK; | |
BR = (BR + 1) & DMASK; | |
if (intrq && ((XR & 017) == 017)) { /* intr, grp of 16? */ | |
PR = err_PC; /* stop for now */ | |
break; | |
} | |
} | |
break; | |
case 021: /* XMS 105721 (OP_N) */ | |
if ((XR & SIGN) || (XR == 0)) break; /* nop? */ | |
dms_viol (err_PC, MVI_PRV); /* priv viol if prot */ | |
while (XR != 0) { | |
dms_wmap (AR, BR); /* AR to map */ | |
XR = (XR - 1) & DMASK; | |
AR = (AR + 1) & DMASK; | |
BR = (BR + 1) & DMASK; | |
if (intrq && ((XR & 017) == 017)) { /* intr, grp of 16? */ | |
PR = err_PC; | |
break; | |
} | |
} | |
break; | |
case 022: /* XMA, XMB 10x722 (OP_N) */ | |
dms_viol (err_PC, MVI_PRV); /* priv viol if prot */ | |
if (ABREG[absel] & 0100000) mapi = UMAP; | |
else mapi = SMAP; | |
if (ABREG[absel] & 0000001) mapj = PBMAP; | |
else mapj = PAMAP; | |
for (i = 0; i < MAP_LNT; i++) { | |
t = dms_rmap (mapi + i); /* read map */ | |
dms_wmap (mapj + i, t); /* write map */ | |
} | |
break; | |
case 024: /* XLA, XLB 10x724 (OP_A) */ | |
ABREG[absel] = ReadWA (op[0].word); /* load alt */ | |
break; | |
case 025: /* XSA, XSB 10x725 (OP_A) */ | |
WriteWA (op[0].word, ABREG[absel]); /* store alt */ | |
break; | |
case 026: /* XCA, XCB 10x726 (OP_A) */ | |
if (ABREG[absel] != ReadWA (op[0].word)) /* compare alt */ | |
PR = (PR + 1) & VAMASK; | |
break; | |
case 027: /* LFA, LFB 10x727 (OP_N) */ | |
if (dms_ump) dms_viol (err_PC, MVI_PRV); /* priv viol if prot */ | |
dms_sr = (dms_sr & ~(MST_FLT | MST_FENCE)) | | |
(ABREG[absel] & (MST_FLT | MST_FENCE)); | |
mp_mem_changed = TRUE; /* set the MP/MEM registers changed flag */ | |
break; | |
case 030: /* RSA, RSB 10x730 (OP_N) */ | |
ABREG [absel] = dms_upd_sr (); /* save stat */ | |
break; | |
case 031: /* RVA, RVB 10x731 (OP_N) */ | |
ABREG [absel] = dms_upd_vr (err_PC); /* return updated violation register */ | |
break; | |
case 032: /* DJP 105732 (OP_A) */ | |
if (dms_ump) dms_viol (err_PC, MVI_PRV); /* priv viol if prot */ | |
dms_enb = 0; /* disable map */ | |
dms_ump = SMAP; | |
mp_dms_jmp (op[0].word, 2); /* validate jump addr */ | |
PCQ_ENTRY; /* save curr P */ | |
PR = op[0].word; /* new P */ | |
ion_defer = TRUE; /* defer interrupts */ | |
break; | |
case 033: /* DJS 105733 (OP_A) */ | |
if (dms_ump) dms_viol (err_PC, MVI_PRV); /* priv viol if prot */ | |
WriteW (op[0].word, PR); /* store ret addr */ | |
PCQ_ENTRY; /* save curr P */ | |
PR = (op[0].word + 1) & VAMASK; /* new P */ | |
dms_enb = 0; /* disable map */ | |
dms_ump = SMAP; | |
ion_defer = TRUE; /* defer intr */ | |
break; | |
case 034: /* SJP 105734 (OP_A) */ | |
if (dms_ump) dms_viol (err_PC, MVI_PRV); /* priv viol if prot */ | |
dms_enb = 1; /* enable system */ | |
dms_ump = SMAP; | |
mp_dms_jmp (op[0].word, 2); /* validate jump addr */ | |
PCQ_ENTRY; /* save curr P */ | |
PR = op[0].word; /* jump */ | |
ion_defer = TRUE; /* defer intr */ | |
break; | |
case 035: /* SJS 105735 (OP_A) */ | |
if (dms_ump) dms_viol (err_PC, MVI_PRV); /* priv viol if prot */ | |
t = PR; /* save retn addr */ | |
PCQ_ENTRY; /* save curr P */ | |
PR = (op[0].word + 1) & VAMASK; /* new P */ | |
dms_enb = 1; /* enable system */ | |
dms_ump = SMAP; | |
WriteW (op[0].word, t); /* store ret addr */ | |
ion_defer = TRUE; /* defer intr */ | |
break; | |
case 036: /* UJP 105736 (OP_A) */ | |
if (dms_ump) dms_viol (err_PC, MVI_PRV); /* priv viol if prot */ | |
dms_enb = 1; /* enable user */ | |
dms_ump = UMAP; | |
mp_dms_jmp (op[0].word, 2); /* validate jump addr */ | |
PCQ_ENTRY; /* save curr P */ | |
PR = op[0].word; /* jump */ | |
ion_defer = TRUE; /* defer intr */ | |
break; | |
case 037: /* UJS 105737 (OP_A) */ | |
if (dms_ump) dms_viol (err_PC, MVI_PRV); /* priv viol if prot */ | |
t = PR; /* save retn addr */ | |
PCQ_ENTRY; /* save curr P */ | |
PR = (op[0].word + 1) & VAMASK; /* new P */ | |
dms_enb = 1; /* enable user */ | |
dms_ump = UMAP; | |
WriteW (op[0].word, t); /* store ret addr */ | |
ion_defer = TRUE; /* defer intr */ | |
break; | |
default: /* others NOP */ | |
break; | |
} | |
return reason; | |
} | |
/* Extended Instruction Group | |
The Extended Instruction Group (EIG) adds 32 index and 10 bit/byte/word | |
manipulation instructions to the 1000 base set. These instructions | |
use the new X and Y index registers that were added to the 1000. | |
Option implementation by CPU was as follows: | |
2114 2115 2116 2100 1000-M 1000-E 1000-F | |
------ ------ ------ ------ ------ ------ ------ | |
N/A N/A N/A N/A std std std | |
The instruction codes are mapped to routines as follows: | |
Instr. 1000-M/E/F Instr. 1000-M/E/F | |
------ ---------- ------ ---------- | |
10x740 S*X 10x760 ISX | |
10x741 C*X 10x761 DSX | |
10x742 L*X 10x762 JLY | |
10x743 STX 10x763 LBT | |
10x744 CX* 10x764 SBT | |
10x745 LDX 10x765 MBT | |
10x746 ADX 10x766 CBT | |
10x747 X*X 10x767 SFB | |
10x750 S*Y 10x770 ISY | |
10x751 C*Y 10x771 DSY | |
10x752 L*Y 10x772 JPY | |
10x753 STY 10x773 SBS | |
10x754 CY* 10x774 CBS | |
10x755 LDY 10x775 TBS | |
10x756 ADY 10x776 CMW | |
10x757 X*Y 10x777 MVW | |
Instructions that use IR bit 11 to select the A or B register are designated | |
with a * above (e.g., 101740 is SAX, and 105740 is SBX). For those that do | |
not use this feature, either the 101xxx or 105xxx code will execute the | |
corresponding instruction, although the 105xxx form is the documented | |
instruction code. | |
Implementation notes: | |
1. The LBT, SBT, MBT, and MVW instructions are used as part of the 2100 IOP | |
implementation. When so called, the MBT and MVW instructions have the | |
additional restriction that the count must be positive. | |
2. The protected memory lower bound for the JLY and JPY instructions is 0. | |
*/ | |
static const OP_PAT op_eig[32] = { | |
OP_A, OP_N, OP_A, OP_A, /* S*X C*X L*X STX */ | |
OP_N, OP_K, OP_K, OP_N, /* CX* LDX ADX X*X */ | |
OP_A, OP_N, OP_A, OP_A, /* S*Y C*Y L*Y STY */ | |
OP_N, OP_K, OP_K, OP_N, /* CY* LDY ADY X*Y */ | |
OP_N, OP_N, OP_A, OP_N, /* ISX DSX JLY LBT */ | |
OP_N, OP_KV, OP_KV, OP_N, /* SBT MBT CBT SFB */ | |
OP_N, OP_N, OP_C, OP_KA, /* ISY DSY JPY SBS */ | |
OP_KA, OP_KK, OP_KV, OP_KV /* CBS TBS CMW MVW */ | |
}; | |
t_stat cpu_eig (uint32 IR, uint32 intrq) | |
{ | |
t_stat reason = SCPE_OK; | |
OPS op; | |
uint8 byte, b1, b2; | |
uint32 entry, absel, sum; | |
HP_WORD t, v1, v2, wc; | |
int32 sop1, sop2; | |
absel = (IR & I_AB)? 1: 0; /* get A/B select */ | |
entry = IR & 037; /* mask to entry point */ | |
if (op_eig [entry] != OP_N) { | |
reason = cpu_ops (op_eig [entry], op, intrq); /* get instruction operands */ | |
if (reason != SCPE_OK) /* evaluation failed? */ | |
return reason; /* return reason for failure */ | |
} | |
switch (entry) { /* decode IR<4:0> */ | |
/* EIG module 1 */ | |
case 000: /* SAX, SBX 10x740 (OP_A) */ | |
op[0].word = (op[0].word + XR) & VAMASK; /* indexed addr */ | |
WriteW (op[0].word, ABREG[absel]); /* store */ | |
break; | |
case 001: /* CAX, CBX 10x741 (OP_N) */ | |
XR = ABREG[absel]; /* copy to XR */ | |
break; | |
case 002: /* LAX, LBX 10x742 (OP_A) */ | |
op[0].word = (op[0].word + XR) & VAMASK; /* indexed addr */ | |
ABREG[absel] = ReadW (op[0].word); /* load */ | |
break; | |
case 003: /* STX 105743 (OP_A) */ | |
WriteW (op[0].word, XR); /* store XR */ | |
break; | |
case 004: /* CXA, CXB 10x744 (OP_N) */ | |
ABREG [absel] = XR; /* copy from XR */ | |
break; | |
case 005: /* LDX 105745 (OP_K)*/ | |
XR = op[0].word; /* load XR */ | |
break; | |
case 006: /* ADX 105746 (OP_K) */ | |
sum = XR + op[0].word; /* add to XR */ | |
if (sum > DMASK) E = 1; /* set E, O */ | |
if (((~XR ^ op[0].word) & (XR ^ sum)) & SIGN) O = 1; | |
XR = sum & DMASK; | |
break; | |
case 007: /* XAX, XBX 10x747 (OP_N) */ | |
t = XR; /* exchange XR */ | |
XR = ABREG [absel]; | |
ABREG [absel] = t; | |
break; | |
case 010: /* SAY, SBY 10x750 (OP_A) */ | |
op[0].word = (op[0].word + YR) & VAMASK; /* indexed addr */ | |
WriteW (op[0].word, ABREG[absel]); /* store */ | |
break; | |
case 011: /* CAY, CBY 10x751 (OP_N) */ | |
YR = ABREG[absel]; /* copy to YR */ | |
break; | |
case 012: /* LAY, LBY 10x752 (OP_A) */ | |
op[0].word = (op[0].word + YR) & VAMASK; /* indexed addr */ | |
ABREG[absel] = ReadW (op[0].word); /* load */ | |
break; | |
case 013: /* STY 105753 (OP_A) */ | |
WriteW (op[0].word, YR); /* store YR */ | |
break; | |
case 014: /* CYA, CYB 10x754 (OP_N) */ | |
ABREG [absel] = YR; /* copy from YR */ | |
break; | |
case 015: /* LDY 105755 (OP_K) */ | |
YR = op[0].word; /* load YR */ | |
break; | |
case 016: /* ADY 105756 (OP_K) */ | |
sum = YR + op[0].word; /* add to YR */ | |
if (sum > DMASK) E = 1; /* set E, O */ | |
if (((~YR ^ op[0].word) & (YR ^ sum)) & SIGN) O = 1; | |
YR = sum & DMASK; | |
break; | |
case 017: /* XAY, XBY 10x757 (OP_N) */ | |
t = YR; /* exchange YR */ | |
YR = ABREG [absel]; | |
ABREG [absel] = t; | |
break; | |
/* EIG module 2 */ | |
case 020: /* ISX 105760 (OP_N) */ | |
XR = (XR + 1) & DMASK; /* incr XR */ | |
if (XR == 0) PR = (PR + 1) & VAMASK; /* skip if zero */ | |
break; | |
case 021: /* DSX 105761 (OP_N) */ | |
XR = (XR - 1) & DMASK; /* decr XR */ | |
if (XR == 0) PR = (PR + 1) & VAMASK; /* skip if zero */ | |
break; | |
case 022: /* JLY 105762 (OP_A) */ | |
mp_dms_jmp (op[0].word, 0); /* validate jump addr */ | |
PCQ_ENTRY; | |
YR = PR; /* ret addr to YR */ | |
PR = op[0].word; /* jump */ | |
break; | |
case 023: /* LBT 105763 (OP_N) */ | |
AR = ReadB (BR); /* load byte */ | |
BR = (BR + 1) & DMASK; /* incr ptr */ | |
break; | |
case 024: /* SBT 105764 (OP_N) */ | |
WriteB (BR, LOWER_BYTE (AR)); /* store byte */ | |
BR = (BR + 1) & DMASK; /* incr ptr */ | |
break; | |
case 025: /* MBT 105765 (OP_KV) */ | |
wc = ReadW (op[1].word); /* get continuation count */ | |
if (wc == 0) wc = op[0].word; /* none? get initiation count */ | |
if ((wc & SIGN) && | |
(UNIT_CPU_TYPE == UNIT_TYPE_2100)) | |
break; /* < 0 is NOP for 2100 IOP */ | |
while (wc != 0) { /* while count */ | |
WriteW (op[1].word, wc); /* for MP abort */ | |
byte = ReadB (AR); /* move byte */ | |
WriteB (BR, byte); | |
AR = (AR + 1) & DMASK; /* incr src */ | |
BR = (BR + 1) & DMASK; /* incr dst */ | |
wc = (wc - 1) & DMASK; /* decr cnt */ | |
if (intrq && wc) { /* intr, more to do? */ | |
PR = err_PC; /* back up P */ | |
break; | |
} | |
} | |
WriteW (op[1].word, wc); /* clean up inline */ | |
break; | |
case 026: /* CBT 105766 (OP_KV) */ | |
wc = ReadW (op[1].word); /* get continuation count */ | |
if (wc == 0) wc = op[0].word; /* none? get initiation count */ | |
while (wc != 0) { /* while count */ | |
WriteW (op[1].word, wc); /* for MP abort */ | |
b1 = ReadB (AR); /* get src1 */ | |
b2 = ReadB (BR); /* get src2 */ | |
if (b1 != b2) { /* compare */ | |
PR = (PR + 1 + (b1 > b2)) & VAMASK; | |
BR = (BR + wc) & DMASK; /* update BR */ | |
wc = 0; /* clr interim */ | |
break; | |
} | |
AR = (AR + 1) & DMASK; /* incr src1 */ | |
BR = (BR + 1) & DMASK; /* incr src2 */ | |
wc = (wc - 1) & DMASK; /* decr cnt */ | |
if (intrq && wc) { /* intr, more to do? */ | |
PR = err_PC; /* back up P */ | |
break; | |
} | |
} | |
WriteW (op[1].word, wc); /* clean up inline */ | |
break; | |
case 027: /* SFB 105767 (OP_N) */ | |
b1 = LOWER_BYTE (AR); /* test byte */ | |
b2 = UPPER_BYTE (AR); /* term byte */ | |
for (;;) { /* scan */ | |
byte = ReadB (BR); /* read byte */ | |
if (byte == b1) break; /* test match? */ | |
BR = (BR + 1) & DMASK; | |
if (byte == b2) { /* term match? */ | |
PR = (PR + 1) & VAMASK; | |
break; | |
} | |
if (intrq) { /* int pending? */ | |
PR = err_PC; /* back up P */ | |
break; | |
} | |
} | |
break; | |
case 030: /* ISY 105770 (OP_N) */ | |
YR = (YR + 1) & DMASK; /* incr YR */ | |
if (YR == 0) PR = (PR + 1) & VAMASK; /* skip if zero */ | |
break; | |
case 031: /* DSY 105771 (OP_N) */ | |
YR = (YR - 1) & DMASK; /* decr YR */ | |
if (YR == 0) PR = (PR + 1) & VAMASK; /* skip if zero */ | |
break; | |
case 032: /* JPY 105772 (OP_C) */ | |
op[0].word = (op[0].word + YR) & VAMASK; /* index, no indir */ | |
mp_dms_jmp (op[0].word, 0); /* validate jump addr */ | |
PCQ_ENTRY; | |
PR = op[0].word; /* jump */ | |
break; | |
case 033: /* SBS 105773 (OP_KA) */ | |
WriteW (op[1].word, /* set bits */ | |
ReadW (op[1].word) | op[0].word); | |
break; | |
case 034: /* CBS 105774 (OP_KA) */ | |
WriteW (op[1].word, /* clear bits */ | |
ReadW (op[1].word) & ~op[0].word); | |
break; | |
case 035: /* TBS 105775 (OP_KK) */ | |
if ((op[1].word & op[0].word) != op[0].word) /* test bits */ | |
PR = (PR + 1) & VAMASK; | |
break; | |
case 036: /* CMW 105776 (OP_KV) */ | |
wc = ReadW (op[1].word); /* get continuation count */ | |
if (wc == 0) wc = op[0].word; /* none? get initiation count */ | |
while (wc != 0) { /* while count */ | |
WriteW (op[1].word, wc); /* for abort */ | |
v1 = ReadW (AR & VAMASK); /* first op */ | |
v2 = ReadW (BR & VAMASK); /* second op */ | |
sop1 = SEXT16 (v1); /* signed */ | |
sop2 = SEXT16 (v2); | |
if (sop1 != sop2) { /* compare */ | |
PR = (PR + 1 + (sop1 > sop2)) & VAMASK; | |
BR = (BR + wc) & DMASK; /* update BR */ | |
wc = 0; /* clr interim */ | |
break; | |
} | |
AR = (AR + 1) & DMASK; /* incr src1 */ | |
BR = (BR + 1) & DMASK; /* incr src2 */ | |
wc = (wc - 1) & DMASK; /* decr cnt */ | |
if (intrq && wc) { /* intr, more to do? */ | |
PR = err_PC; /* back up P */ | |
break; | |
} | |
} | |
WriteW (op[1].word, wc); /* clean up inline */ | |
break; | |
case 037: /* MVW 105777 (OP_KV) */ | |
wc = ReadW (op[1].word); /* get continuation count */ | |
if (wc == 0) wc = op[0].word; /* none? get initiation count */ | |
if ((wc & SIGN) && | |
(UNIT_CPU_TYPE == UNIT_TYPE_2100)) | |
break; /* < 0 is NOP for 2100 IOP */ | |
while (wc != 0) { /* while count */ | |
WriteW (op[1].word, wc); /* for abort */ | |
t = ReadW (AR & VAMASK); /* move word */ | |
WriteW (BR & VAMASK, t); | |
AR = (AR + 1) & DMASK; /* incr src */ | |
BR = (BR + 1) & DMASK; /* incr dst */ | |
wc = (wc - 1) & DMASK; /* decr cnt */ | |
if (intrq && wc) { /* intr, more to do? */ | |
PR = err_PC; /* back up P */ | |
break; | |
} | |
} | |
WriteW (op[1].word, wc); /* clean up inline */ | |
break; | |
} | |
return reason; | |
} | |
/* 2000 I/O Processor | |
The IOP accelerates certain operations of the HP 2000 Time-Share BASIC system | |
I/O processor. Most 2000 systems were delivered with 2100 CPUs, although IOP | |
microcode was developed for the 1000-M and 1000-E. As the I/O processors | |
were specific to the 2000 system, general compatibility with other CPU | |
microcode options was unnecessary, and indeed no other options were possible | |
for the 2100. | |
Option implementation by CPU was as follows: | |
2114 2115 2116 2100 1000-M 1000-E 1000-F | |
------ ------ ------ ------ ------ ------ ------ | |
N/A N/A N/A 13206A 13207A 22702A N/A | |
The routines are mapped to instruction codes as follows: | |
Instr. 2100 1000-M/E Description | |
------ ---------- ---------- -------------------------------------------- | |
SAI 105060-117 101400-037 Store A indexed by B (+/- offset in IR<4:0>) | |
LAI 105020-057 105400-037 Load A indexed by B (+/- offset in IR<4:0>) | |
CRC 105150 105460 Generate CRC | |
REST 105340 105461 Restore registers from stack | |
READF 105220 105462 Read F register (stack pointer) | |
INS -- 105463 Initialize F register (stack pointer) | |
ENQ 105240 105464 Enqueue | |
PENQ 105257 105465 Priority enqueue | |
DEQ 105260 105466 Dequeue | |
TRSLT 105160 105467 Translate character | |
ILIST 105000 105470 Indirect address list (similar to $SETP) | |
PRFEI 105222 105471 Power fail exit with I/O | |
PRFEX 105223 105472 Power fail exit | |
PRFIO 105221 105473 Power fail I/O | |
SAVE 105362 105474 Save registers to stack | |
MBYTE 105120 105765 Move bytes (MBT) | |
MWORD 105200 105777 Move words (MVW) | |
SBYTE 105300 105764 Store byte (SBT) | |
LBYTE 105320 105763 Load byte (LBT) | |
The INS instruction was not required in the 2100 implementation because the | |
stack pointer was actually the memory protect fence register and so could be | |
loaded directly with an OTA/B 05. Also, the 1000 implementation did not | |
offer the MBYTE, MWORD, SBYTE, and LBYTE instructions because the equivalent | |
instructions from the standard Extended Instruction Group were used instead. | |
Note that the 2100 MBYTE and MWORD instructions operate slightly differently | |
from the 1000 MBT and MVW instructions. Specifically, the move count is | |
signed on the 2100 and unsigned on the 1000. A negative count on the 2100 | |
results in a NOP. | |
The simulator remaps the 2100 instructions to the 1000 codes. The four EIG | |
equivalents are dispatched to the EIG simulator. The rest are handled here. | |
Additional reference: | |
- HP 2000 Computer System Sources and Listings Documentation | |
(22687-90020, undated), section 3, pages 2-74 through 2-91. | |
*/ | |
static const OP_PAT op_iop[16] = { | |
OP_V, OP_N, OP_N, OP_N, /* CRC RESTR READF INS */ | |
OP_N, OP_N, OP_N, OP_V, /* ENQ PENQ DEQ TRSLT */ | |
OP_AC, OP_CVA, OP_A, OP_CV, /* ILIST PRFEI PRFEX PRFIO */ | |
OP_N, OP_N, OP_N, OP_N /* SAVE --- --- --- */ | |
}; | |
t_stat cpu_iop (uint32 IR, uint32 intrq) | |
{ | |
t_stat reason = SCPE_OK; | |
OPS op; | |
uint8 byte; | |
uint32 entry, i; | |
HP_WORD hp, tp, t, wc, MA; | |
if (UNIT_CPU_TYPE == UNIT_TYPE_2100) { /* 2100 IOP? */ | |
if ((IR >= 0105020) && (IR <= 0105057)) /* remap LAI */ | |
IR = 0105400 | (IR - 0105020); | |
else if ((IR >= 0105060) && (IR <= 0105117)) /* remap SAI */ | |
IR = 0101400 | (IR - 0105060); | |
else { | |
switch (IR) { /* remap others */ | |
case 0105000: IR = 0105470; break; /* ILIST */ | |
case 0105120: return cpu_eig (0105765, intrq); /* MBYTE (maps to MBT) */ | |
case 0105150: IR = 0105460; break; /* CRC */ | |
case 0105160: IR = 0105467; break; /* TRSLT */ | |
case 0105200: return cpu_eig (0105777, intrq); /* MWORD (maps to MVW) */ | |
case 0105220: IR = 0105462; break; /* READF */ | |
case 0105221: IR = 0105473; break; /* PRFIO */ | |
case 0105222: IR = 0105471; break; /* PRFEI */ | |
case 0105223: IR = 0105472; break; /* PRFEX */ | |
case 0105240: IR = 0105464; break; /* ENQ */ | |
case 0105257: IR = 0105465; break; /* PENQ */ | |
case 0105260: IR = 0105466; break; /* DEQ */ | |
case 0105300: return cpu_eig (0105764, intrq); /* SBYTE (maps to SBT) */ | |
case 0105320: return cpu_eig (0105763, intrq); /* LBYTE (maps to LBT) */ | |
case 0105340: IR = 0105461; break; /* REST */ | |
case 0105362: IR = 0105474; break; /* SAVE */ | |
default: /* all others invalid */ | |
return STOP (cpu_ss_unimpl); | |
} | |
} | |
} | |
entry = IR & 077; /* mask to entry point */ | |
if (entry <= 037) { /* LAI/SAI 10x400-437 */ | |
MA = ((entry - 020) + BR) & VAMASK; /* +/- offset */ | |
if (IR & I_AB) AR = ReadW (MA); /* AB = 1 -> LAI */ | |
else WriteW (MA, AR); /* AB = 0 -> SAI */ | |
return reason; | |
} | |
else if (entry <= 057) /* IR = 10x440-457? */ | |
return STOP (cpu_ss_unimpl); /* not part of IOP */ | |
entry = entry - 060; /* offset 10x460-477 */ | |
if (op_iop [entry] != OP_N) { | |
reason = cpu_ops (op_iop [entry], op, intrq); /* get instruction operands */ | |
if (reason != SCPE_OK) /* evaluation failed? */ | |
return reason; /* return reason for failure */ | |
} | |
switch (entry) { /* decode IR<5:0> */ | |
case 000: /* CRC 105460 (OP_V) */ | |
t = ReadW (op[0].word) ^ (AR & 0377); /* xor prev CRC and char */ | |
for (i = 0; i < 8; i++) { /* apply polynomial */ | |
t = (t >> 1) | ((t & 1) << 15); /* rotate right */ | |
if (t & SIGN) t = t ^ 020001; /* old t<0>? xor */ | |
} | |
WriteW (op[0].word, t); /* rewrite CRC */ | |
break; | |
case 001: /* RESTR 105461 (OP_N) */ | |
iop_sp = (iop_sp - 1) & VAMASK; /* decr stack ptr */ | |
t = ReadW (iop_sp); /* get E and O */ | |
O = ((t >> 1) ^ 1) & 1; /* restore O */ | |
E = t & 1; /* restore E */ | |
iop_sp = (iop_sp - 1) & VAMASK; /* decr sp */ | |
BR = ReadW (iop_sp); /* restore B */ | |
iop_sp = (iop_sp - 1) & VAMASK; /* decr sp */ | |
AR = ReadW (iop_sp); /* restore A */ | |
if (UNIT_CPU_MODEL == UNIT_2100) | |
mp_fence = iop_sp; /* 2100 keeps sp in MP FR */ | |
break; | |
case 002: /* READF 105462 (OP_N) */ | |
AR = iop_sp; /* copy stk ptr */ | |
break; | |
case 003: /* INS 105463 (OP_N) */ | |
iop_sp = AR; /* init stk ptr */ | |
break; | |
case 004: /* ENQ 105464 (OP_N) */ | |
hp = ReadW (AR & VAMASK); /* addr of head */ | |
tp = ReadW ((AR + 1) & VAMASK); /* addr of tail */ | |
WriteW ((BR - 1) & VAMASK, 0); /* entry link */ | |
WriteW ((tp - 1) & VAMASK, BR); /* tail link */ | |
WriteW ((AR + 1) & VAMASK, BR); /* queue tail */ | |
if (hp != 0) PR = (PR + 1) & VAMASK; /* q not empty? skip */ | |
break; | |
case 005: /* PENQ 105465 (OP_N) */ | |
hp = ReadW (AR & VAMASK); /* addr of head */ | |
WriteW ((BR - 1) & VAMASK, hp); /* becomes entry link */ | |
WriteW (AR & VAMASK, BR); /* queue head */ | |
if (hp == 0) /* q empty? */ | |
WriteW ((AR + 1) & VAMASK, BR); /* queue tail */ | |
else PR = (PR + 1) & VAMASK; /* skip */ | |
break; | |
case 006: /* DEQ 105466 (OP_N) */ | |
BR = ReadW (AR & VAMASK); /* addr of head */ | |
if (BR) { /* queue not empty? */ | |
hp = ReadW ((BR - 1) & VAMASK); /* read hd entry link */ | |
WriteW (AR & VAMASK, hp); /* becomes queue head */ | |
if (hp == 0) /* q now empty? */ | |
WriteW ((AR + 1) & VAMASK, (AR + 1) & DMASK); | |
PR = (PR + 1) & VAMASK; /* skip */ | |
} | |
break; | |
case 007: /* TRSLT 105467 (OP_V) */ | |
wc = ReadW (op[0].word); /* get count */ | |
if (wc & SIGN) break; /* cnt < 0? */ | |
while (wc != 0) { /* loop */ | |
MA = (AR + AR + ReadB (BR)) & VAMASK; | |
byte = ReadB (MA); /* xlate */ | |
WriteB (BR, byte); /* store char */ | |
BR = (BR + 1) & DMASK; /* incr ptr */ | |
wc = (wc - 1) & DMASK; /* decr cnt */ | |
if (wc && intrq) { /* more and intr? */ | |
WriteW (op[0].word, wc); /* save count */ | |
PR = err_PC; /* stop for now */ | |
break; | |
} | |
} | |
break; | |
case 010: /* ILIST 105470 (OP_AC) */ | |
do { /* for count */ | |
WriteW (op[0].word, AR); /* write AR to mem */ | |
AR = (AR + 1) & DMASK; /* incr AR */ | |
op[0].word = (op[0].word + 1) & VAMASK; /* incr MA */ | |
op[1].word = (op[1].word - 1) & DMASK; /* decr count */ | |
} | |
while (op[1].word != 0); | |
break; | |
case 011: /* PRFEI 105471 (OP_CVA) */ | |
WriteW (op[1].word, 1); /* set flag */ | |
reason = cpu_iog (op[0].word, 0); /* execute I/O instr */ | |
op[0].word = op[2].word; /* set rtn and fall through */ | |
case 012: /* PRFEX 105472 (OP_A) */ | |
PCQ_ENTRY; | |
PR = ReadW (op[0].word) & VAMASK; /* jump indirect */ | |
WriteW (op[0].word, 0); /* clear exit */ | |
break; | |
case 013: /* PRFIO 105473 (OP_CV) */ | |
WriteW (op[1].word, 1); /* set flag */ | |
reason = cpu_iog (op[0].word, 0); /* execute instr */ | |
break; | |
case 014: /* SAVE 105474 (OP_N) */ | |
WriteW (iop_sp, AR); /* save A */ | |
iop_sp = (iop_sp + 1) & VAMASK; /* incr stack ptr */ | |
WriteW (iop_sp, BR); /* save B */ | |
iop_sp = (iop_sp + 1) & VAMASK; /* incr stack ptr */ | |
t = (HP_WORD) ((O ^ 1) << 1 | E); /* merge E and O */ | |
WriteW (iop_sp, t); /* save E and O */ | |
iop_sp = (iop_sp + 1) & VAMASK; /* incr stack ptr */ | |
if (UNIT_CPU_TYPE == UNIT_TYPE_2100) | |
mp_fence = iop_sp; /* 2100 keeps sp in MP FR */ | |
break; | |
default: /* instruction unimplemented */ | |
return STOP (cpu_ss_unimpl); | |
} | |
return reason; | |
} |