/* i8237.c: Intel 8237 DMA adapter | |
Copyright (c) 2016, William A. Beech | |
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 | |
WILLIAM A. BEECH 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 William A. Beech shall not be | |
used in advertising or otherwise to promote the sale, use or other dealings | |
in this Software without prior written authorization from William A. Beech. | |
MODIFICATIONS: | |
11 Jul 16 - Original file. | |
NOTES: | |
Default is none. Since all channel registers in the i8237 are 16-bit, transfers | |
are done as two 8-bit operations, low- then high-byte. | |
Port addressing is as follows (Port offset = 0): | |
Port Mode Command Function | |
00 Write Load DMAC Channel 0 Base and Current Address Regsiters | |
Read Read DMAC Channel 0 Current Address Register | |
01 Write Load DMAC Channel 0 Base and Current Word Count Registers | |
Read Read DMAC Channel 0 Current Word Count Register | |
04 Write Load DMAC Channel 2 Base and Current Address Regsiters | |
Read Read DMAC Channel 2 Current Address Register | |
05 Write Load DMAC Channel 2 Base and Current Word Count Registers | |
Read Read DMAC Channel 2 Current Word Count Register | |
06 Write Load DMAC Channel 3 Base and Current Address Regsiters | |
Read Read DMAC Channel 3 Current Address Register | |
07 Write Load DMAC Channel 3 Base and Current Word Count Registers | |
Read Read DMAC Channel 3 Current Word Count Register | |
08 Write Load DMAC Command Register | |
Read Read DMAC Status Register | |
09 Write Load DMAC Request Register | |
0A Write Set/Reset DMAC Mask Register | |
0B Write Load DMAC Mode Register | |
0C Write Clear DMAC First/Last Flip-Flop | |
0D Write DMAC Master Clear | |
0F Write Load DMAC Mask Register | |
Register usage is defined in the following paragraphs. | |
Read/Write DMAC Address Registers | |
Used to simultaneously load a channel's current-address register and base-address | |
register with the memory address of the first byte to be transferred. (The Channel | |
0 current/base address register must be loaded prior to initiating a diskette read | |
or write operation.) Since each channel's address registers are 16 bits in length | |
(64K address range), two "write address register" commands must be executed in | |
order to load the complete current/base address registers for any channel. | |
Read/Write DMAC Word Count Registers | |
The Write DMAC Word Count Register command is used to simultaneously load a | |
channel's current and base word-count registers with the number of bytes | |
to be transferred during a subsequent DMA operation. Since the word-count | |
registers are 16-bits in length, two commands must be executed to load both | |
halves of the registers. | |
Write DMAC Command Register | |
The Write DMAC Command Register command loads an 8-bit byte into the | |
DMAC's command register to define the operating characteristics of the | |
DMAC. The functions of the individual bits in the command register are | |
defined in the following diagram. Note that only two bits within the | |
register are applicable to the controller; the remaining bits select | |
functions that are not supported and, accordingly, must always be set | |
to zero. | |
7 6 5 4 3 2 1 0 | |
+---+---+---+---+---+---+---+---+ | |
| 0 0 0 0 0 0 | | |
+---+---+---+---+---+---+---+---+ | |
| | | |
| +---------- 0 CONTROLLER ENABLE | |
| 1 CONTROLLER DISABLE | |
| | |
+------------------ 0 FIXED PRIORITY | |
1 ROTATING PRIORITY | |
Read DMAC Status Register Command | |
The Read DMAC Status Register command accesses an 8-bit status byte that | |
identifies the DMA channels that have reached terminal count or that | |
have a pending DMA request. | |
7 6 5 4 3 2 1 0 | |
+---+---+---+---+---+---+---+---+ | |
| 0 0 | | |
+---+---+---+---+---+---+---+---+ | |
| | | | | | | |
| | | | | +-- CHANNEL 0 TC | |
| | | | +---------- CHANNEL 2 TC | |
| | | +-------------- CHANNEL 3 TC | |
| | +------------------ CHANNEL 0 DMA REQUEST | |
| +-------------------------- CHANNEL 2 DMA REQUEST | |
+------------------------------ CHANNEL 3 DMA REQUEST | |
Write DMAC Request Register | |
The data byte associated with the Write DMAC Request Register command | |
sets or resets a channel's associated request bit within the DMAC's | |
internal 4-bit request register. | |
7 6 5 4 3 2 1 0 | |
+---+---+---+---+---+---+---+---+ | |
| X X X X X | | |
+---+---+---+---+---+---+---+---+ | |
| | | | |
| +---+-- 00 SELECT CHANNEL 0 | |
| 01 SELECT CHANNEL 1 | |
| 10 SELECT CHANNEL 2 | |
| 11 SELECT CHANNEL 3 | |
| | |
+---------- 0 RESET REQUEST BIT | |
1 SET REQUEST BIT | |
Set/Reset DMAC Mask Register | |
Prior to a DREQ-initiated DMA transfer, the channel's mask bit must | |
be reset to enable recognition of the DREQ input. When the transfer | |
is complete (terminal count reached or external EOP applied) and | |
the channel is not programmed to autoinitialize, the channel's | |
mask bit is automatically set (disabling DREQ) and must be reset | |
prior to a subsequent DMA transfer. All four bits of the mask | |
register are set (disabling the DREQ inputs) by a DMAC master | |
clear or controller reset. Additionally, all four bits can be | |
set/reset by a single Write DMAC Mask Register command. | |
7 6 5 4 3 2 1 0 | |
+---+---+---+---+---+---+---+---+ | |
| X X X X X | | |
+---+---+---+---+---+---+---+---+ | |
| | | | |
| +---+-- 00 SELECT CHANNEL 0 | |
| 01 SELECT CHANNEL 1 | |
| 10 SELECT CHANNEL 2 | |
| 11 SELECT CHANNEL 3 | |
| | |
+---------- 0 RESET REQUEST BIT | |
1 SET REQUEST BIT | |
Write DMAC Mode Register | |
The Write DMAC Mode Register command is used to define the | |
operating mode characteristics for each DMA channel. Each | |
channel has an internal 6-bit mode register; the high-order | |
six bits of the associated data byte are written into the | |
mode register addressed by the two low-order bits. | |
7 6 5 4 3 2 1 0 | |
+---+---+---+---+---+---+---+---+ | |
| | | |
+---+---+---+---+---+---+---+---+ | |
| | | | | | | | | |
| | | | | | +---+-- 00 SELECT CHANNEL 0 | |
| | | | | | 01 SELECT CHANNEL 1 | |
| | | | | | 10 SELECT CHANNEL 2 | |
| | | | | | 11 SELECT CHANNEL 3 | |
| | | | | | | |
| | | | +---+---------- 00 VERIFY TRANSFER | |
| | | | 01 WRITE TRANSFER | |
| | | | 10 READ TRANSFER | |
| | | | | |
| | | +------------------ 0 AUTOINITIALIZE DISABLE | |
| | | 1 AUTOINITIALIZE ENABLE | |
| | | | |
| | +---------------------- 0 ADDRESS INCREMENT | |
| | 1 ADDRESS DECREMENT | |
| | | |
+---+-------------------------- 00 DEMAND MODE | |
01 SINGLE MODE | |
10 BLOCK MODE | |
Clear DMAC First/Last Flip-Flop | |
The Clear DMAC First/Last Flip-Flop command initializes | |
the DMAC's internal first/last flip-flop so that the | |
next byte written to or re~d from the 16-bit address | |
or word-count registers is the low-order byte. The | |
flip-flop is toggled with each register access so that | |
a second register read or write command accesses the | |
high-order byte. | |
DMAC Master Clear | |
The DMAC Master Clear command clears the DMAC's command, status, | |
request, and temporary registers to zero, initializes the | |
first/last flip-flop, and sets the four channel mask bits in | |
the mask register to disable all DMA requests (i.e., the DMAC | |
is placed in an idle state). | |
Write DMAC Mask Register | |
The Write DMAC Mask Register command allows all four bits of the | |
DMAC's mask register to be written with a single command. | |
7 6 5 4 3 2 1 0 | |
+---+---+---+---+---+---+---+---+ | |
| X X X X X | | |
+---+---+---+---+---+---+---+---+ | |
| | | | |
| | +-- 0 CLEAR CHANNEL 0 MASK BIT | |
| | 1 SET CHANNEL 0 MASK BIT | |
| | | |
| +---------- 0 CLEAR CHANNEL 2 MASK BIT | |
| 1 SET CHANNEL 2 MASK BIT | |
| | |
+-------------- 0 CLEAR CHANNEL 3 MASK BIT | |
1 SET CHANNEL 3 MASK BIT | |
*/ | |
#include "system_defs.h" | |
/* external globals */ | |
extern uint16 port; //port called in dev_table[port] | |
/* globals */ | |
int32 i8237_devnum = 0; //actual number of 8253 instances + 1 | |
uint16 i8237_port[4]; //base port registered to each instance | |
/* internal function prototypes */ | |
t_stat i8237_svc (UNIT *uptr); | |
t_stat i8237_reset (DEVICE *dptr, uint16 base); | |
void i8237_reset1 (void); | |
t_stat i8237_set_mode (UNIT *uptr, int32 val, CONST char *cptr, void *desc); | |
uint8 i8237_r0x(t_bool io, uint8 data); | |
uint8 i8237_r1x(t_bool io, uint8 data); | |
uint8 i8237_r2x(t_bool io, uint8 data); | |
uint8 i8237_r3x(t_bool io, uint8 data); | |
uint8 i8237_r4x(t_bool io, uint8 data); | |
uint8 i8237_r5x(t_bool io, uint8 data); | |
uint8 i8237_r6x(t_bool io, uint8 data); | |
uint8 i8237_r7x(t_bool io, uint8 data); | |
uint8 i8237_r8x(t_bool io, uint8 data); | |
uint8 i8237_r9x(t_bool io, uint8 data); | |
uint8 i8237_rAx(t_bool io, uint8 data); | |
uint8 i8237_rBx(t_bool io, uint8 data); | |
uint8 i8237_rCx(t_bool io, uint8 data); | |
uint8 i8237_rDx(t_bool io, uint8 data); | |
uint8 i8237_rEx(t_bool io, uint8 data); | |
uint8 i8237_rFx(t_bool io, uint8 data); | |
/* external function prototypes */ | |
extern uint16 reg_dev(uint8 (*routine)(t_bool, uint8), uint16); | |
/* 8237 physical register definitions */ | |
uint16 i8237_r0; // 8237 ch 0 address register | |
uint16 i8237_r1; // 8237 ch 0 count register | |
uint16 i8237_r2; // 8237 ch 1 address register | |
uint16 i8237_r3; // 8237 ch 1 count register | |
uint16 i8237_r4; // 8237 ch 2 address register | |
uint16 i8237_r5; // 8237 ch 2 count register | |
uint16 i8237_r6; // 8237 ch 3 address register | |
uint16 i8237_r7; // 8237 ch 3 count register | |
uint8 i8237_r8; // 8237 status register | |
uint8 i8237_r9; // 8237 command register | |
uint8 i8237_rA; // 8237 mode register | |
uint8 i8237_rB; // 8237 mask register | |
uint8 i8237_rC; // 8237 request register | |
uint8 i8237_rD; // 8237 first/last ff | |
uint8 i8237_rE; // 8237 | |
uint8 i8237_rF; // 8237 | |
/* i8237 physical register definitions */ | |
uint16 i8237_sr; // isbc-208 segment register | |
uint8 i8237_i; // iSBC-208 interrupt register | |
uint8 i8237_a; // iSBC-208 auxillary port register | |
/* i8237 Standard SIMH Device Data Structures - 1 unit */ | |
UNIT i8237_unit[] = { | |
{ UDATA (0, 0, 0) ,20 }, /* i8237 0 */ | |
{ UDATA (0, 0, 0) ,20 }, /* i8237 1 */ | |
{ UDATA (0, 0, 0) ,20 }, /* i8237 2 */ | |
{ UDATA (0, 0, 0) ,20 } /* i8237 3 */ | |
}; | |
REG i8237_reg[] = { | |
{ HRDATA (CH0ADR, i8237_r0, 16) }, | |
{ HRDATA (CH0CNT, i8237_r1, 16) }, | |
{ HRDATA (CH1ADR, i8237_r2, 16) }, | |
{ HRDATA (CH1CNT, i8237_r3, 16) }, | |
{ HRDATA (CH2ADR, i8237_r4, 16) }, | |
{ HRDATA (CH2CNT, i8237_r5, 16) }, | |
{ HRDATA (CH3ADR, i8237_r6, 16) }, | |
{ HRDATA (CH3CNT, i8237_r7, 16) }, | |
{ HRDATA (STAT37, i8237_r8, 8) }, | |
{ HRDATA (CMD37, i8237_r9, 8) }, | |
{ HRDATA (MODE, i8237_rA, 8) }, | |
{ HRDATA (MASK, i8237_rB, 8) }, | |
{ HRDATA (REQ, i8237_rC, 8) }, | |
{ HRDATA (FF, i8237_rD, 8) }, | |
{ HRDATA (SEGREG, i8237_sr, 8) }, | |
{ HRDATA (AUX, i8237_a, 8) }, | |
{ HRDATA (INT, i8237_i, 8) }, | |
{ NULL } | |
}; | |
MTAB i8237_mod[] = { | |
{ 0 } | |
}; | |
DEBTAB i8237_debug[] = { | |
{ "ALL", DEBUG_all }, | |
{ "FLOW", DEBUG_flow }, | |
{ "READ", DEBUG_read }, | |
{ "WRITE", DEBUG_write }, | |
{ "LEV1", DEBUG_level1 }, | |
{ "LEV2", DEBUG_level2 }, | |
{ "REG", DEBUG_reg }, | |
{ NULL } | |
}; | |
DEVICE i8237_dev = { | |
"8237", //name | |
i8237_unit, //units | |
i8237_reg, //registers | |
i8237_mod, //modifiers | |
1, //numunits | |
16, //aradix | |
32, //awidth | |
1, //aincr | |
16, //dradix | |
8, //dwidth | |
NULL, //examine | |
NULL, //deposit | |
// &i8237_reset, //deposit | |
NULL, //reset | |
NULL, //boot | |
NULL, //attach | |
NULL, //detach | |
NULL, //ctxt | |
DEV_DEBUG+DEV_DISABLE+DEV_DIS, //flags | |
0, //dctrl | |
// DEBUG_flow + DEBUG_read + DEBUG_write, //dctrl | |
i8237_debug, //debflags | |
NULL, //msize | |
NULL //lname | |
}; | |
/* Service routines to handle simulator functions */ | |
/* service routine - actually does the simulated DMA */ | |
t_stat i8237_svc(UNIT *uptr) | |
{ | |
sim_printf("uptr=%08X\n", (long) uptr); | |
sim_activate (&i8237_unit[uptr->u6], i8237_unit[uptr->u6].wait); | |
return SCPE_OK; | |
} | |
/* Reset routine */ | |
t_stat i8237_reset(DEVICE *dptr, uint16 base) | |
{ | |
if (i8237_devnum > I8237_NUM) { | |
sim_printf("i8237_reset: too many devices!\n"); | |
return SCPE_MEM; | |
} | |
i8237_port[i8237_devnum] = reg_dev(i8237_r0x, base); | |
reg_dev(i8237_r1x, base + 1); | |
reg_dev(i8237_r2x, base + 2); | |
reg_dev(i8237_r3x, base + 3); | |
reg_dev(i8237_r4x, base + 4); | |
reg_dev(i8237_r5x, base + 5); | |
reg_dev(i8237_r6x, base + 6); | |
reg_dev(i8237_r7x, base + 7); | |
reg_dev(i8237_r8x, base + 8); | |
reg_dev(i8237_r9x, base + 9); | |
reg_dev(i8237_rAx, base + 10); | |
reg_dev(i8237_rBx, base + 11); | |
reg_dev(i8237_rCx, base + 12); | |
reg_dev(i8237_rDx, base + 13); | |
reg_dev(i8237_rEx, base + 14); | |
reg_dev(i8237_rFx, base + 15); | |
sim_printf(" 8237 Reset\n"); | |
sim_printf(" 8237: Registered at %03X\n", base); | |
sim_activate (&i8237_unit[i8237_devnum], i8237_unit[i8237_devnum].wait); /* activate unit */ | |
if ((i8237_dev.flags & DEV_DIS) == 0) | |
i8237_reset1(); | |
i8237_devnum++; | |
return SCPE_OK; | |
} | |
uint8 i8237_get_dn(void) | |
{ | |
int i; | |
for (i=0; i<I8237_NUM; i++) | |
if (port >=i8237_port[i] && port <= i8237_port[i] + 16) | |
return i; | |
sim_printf("i8237_get_dn: port %03X not in 8237 device table\n", port); | |
return 0xFF; | |
} | |
void i8237_reset1(void) | |
{ | |
int32 i; | |
UNIT *uptr; | |
static int flag = 1; | |
for (i = 0; i < 1; i++) { /* handle all units */ | |
uptr = i8237_dev.units + i; | |
if (uptr->capac == 0) { /* if not configured */ | |
// sim_printf(" SBC208%d: Not configured\n", i); | |
// if (flag) { | |
// sim_printf(" ALL: \"set isbc208 en\"\n"); | |
// sim_printf(" EPROM: \"att isbc2080 <filename>\"\n"); | |
// flag = 0; | |
// } | |
uptr->capac = 0; /* initialize unit */ | |
uptr->u3 = 0; | |
uptr->u4 = 0; | |
uptr->u5 = 0; | |
uptr->u6 = i; /* unit number - only set here! */ | |
sim_activate (&i8237_unit[uptr->u6], i8237_unit[uptr->u6].wait); | |
} else { | |
// sim_printf(" SBC208%d: Configured, Attached to %s\n", i, uptr->filename); | |
} | |
} | |
i8237_r8 = 0; /* status */ | |
i8237_r9 = 0; /* command */ | |
i8237_rB = 0x0F; /* mask */ | |
i8237_rC = 0; /* request */ | |
i8237_rD = 0; /* first/last FF */ | |
} | |
/* i8237 set mode = 8- or 16-bit data bus */ | |
/* always 8-bit mode for current simulators */ | |
t_stat i8237_set_mode(UNIT *uptr, int32 val, CONST char *cptr, void *desc) | |
{ | |
sim_debug (DEBUG_flow, &i8237_dev, " i8237_set_mode: Entered with val=%08XH uptr->flags=%08X\n", val, uptr->flags); | |
sim_debug (DEBUG_flow, &i8237_dev, " i8237_set_mode: Done\n"); | |
return SCPE_OK; | |
} | |
/* I/O instruction handlers, called from the CPU module when an | |
IN or OUT instruction is issued. | |
Each function is passed an 'io' flag, where 0 means a read from | |
the port, and 1 means a write to the port. On input, the actual | |
input is passed as the return value, on output, 'data' is written | |
to the device. | |
*/ | |
uint8 i8237_r0x(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { /* read current address CH 0 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r0(H) read as %04X\n", i8237_r0); | |
return (i8237_r0 >> 8); | |
} else { /* low byte */ | |
i8237_rD++; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r0(L) read as %04X\n", i8237_r0); | |
return (i8237_r0 & 0xFF); | |
} | |
} else { /* write base & current address CH 0 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
i8237_r0 |= (data << 8); | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r0(H) set to %04X\n", i8237_r0); | |
} else { /* low byte */ | |
i8237_rD++; | |
i8237_r0 = data & 0xFF; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r0(L) set to %04X\n", i8237_r0); | |
} | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_r1x(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { /* read current word count CH 0 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r1(H) read as %04X\n", i8237_r1); | |
return (i8237_r1 >> 8); | |
} else { /* low byte */ | |
i8237_rD++; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r1(L) read as %04X\n", i8237_r1); | |
return (i8237_r1 & 0xFF); | |
} | |
} else { /* write base & current address CH 0 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
i8237_r1 |= (data << 8); | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r1(H) set to %04X\n", i8237_r1); | |
} else { /* low byte */ | |
i8237_rD++; | |
i8237_r1 = data & 0xFF; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r1(L) set to %04X\n", i8237_r1); | |
} | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_r2x(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { /* read current address CH 1 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r2(H) read as %04X\n", i8237_r2); | |
return (i8237_r2 >> 8); | |
} else { /* low byte */ | |
i8237_rD++; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r2(L) read as %04X\n", i8237_r2); | |
return (i8237_r2 & 0xFF); | |
} | |
} else { /* write base & current address CH 1 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
i8237_r2 |= (data << 8); | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r2(H) set to %04X\n", i8237_r2); | |
} else { /* low byte */ | |
i8237_rD++; | |
i8237_r2 = data & 0xFF; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r2(L) set to %04X\n", i8237_r2); | |
} | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_r3x(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { /* read current word count CH 1 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r3(H) read as %04X\n", i8237_r3); | |
return (i8237_r3 >> 8); | |
} else { /* low byte */ | |
i8237_rD++; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r3(L) read as %04X\n", i8237_r3); | |
return (i8237_r3 & 0xFF); | |
} | |
} else { /* write base & current address CH 1 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
i8237_r3 |= (data << 8); | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r3(H) set to %04X\n", i8237_r3); | |
} else { /* low byte */ | |
i8237_rD++; | |
i8237_r3 = data & 0xFF; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r3(L) set to %04X\n", i8237_r3); | |
} | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_r4x(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { /* read current address CH 2 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r4(H) read as %04X\n", i8237_r4); | |
return (i8237_r4 >> 8); | |
} else { /* low byte */ | |
i8237_rD++; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r4(L) read as %04X\n", i8237_r4); | |
return (i8237_r4 & 0xFF); | |
} | |
} else { /* write base & current address CH 2 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
i8237_r4 |= (data << 8); | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r4(H) set to %04X\n", i8237_r4); | |
} else { /* low byte */ | |
i8237_rD++; | |
i8237_r4 = data & 0xFF; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r4(L) set to %04X\n", i8237_r4); | |
} | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_r5x(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { /* read current word count CH 2 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r5(H) read as %04X\n", i8237_r5); | |
return (i8237_r5 >> 8); | |
} else { /* low byte */ | |
i8237_rD++; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r5(L) read as %04X\n", i8237_r5); | |
return (i8237_r5 & 0xFF); | |
} | |
} else { /* write base & current address CH 2 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
i8237_r5 |= (data << 8); | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r5(H) set to %04X\n", i8237_r5); | |
} else { /* low byte */ | |
i8237_rD++; | |
i8237_r5 = data & 0xFF; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r5(L) set to %04X\n", i8237_r5); | |
} | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_r6x(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { /* read current address CH 3 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r6(H) read as %04X\n", i8237_r6); | |
return (i8237_r6 >> 8); | |
} else { /* low byte */ | |
i8237_rD++; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r6(L) read as %04X\n", i8237_r6); | |
return (i8237_r6 & 0xFF); | |
} | |
} else { /* write base & current address CH 3 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
i8237_r6 |= (data << 8); | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r6(H) set to %04X\n", i8237_r6); | |
} else { /* low byte */ | |
i8237_rD++; | |
i8237_r6 = data & 0xFF; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r6(L) set to %04X\n", i8237_r6); | |
} | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_r7x(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { /* read current word count CH 3 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r7(H) read as %04X\n", i8237_r7); | |
return (i8237_r7 >> 8); | |
} else { /* low byte */ | |
i8237_rD++; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r7(L) read as %04X\n", i8237_r7); | |
return (i8237_r7 & 0xFF); | |
} | |
} else { /* write base & current address CH 3 */ | |
if (i8237_rD) { /* high byte */ | |
i8237_rD = 0; | |
i8237_r7 |= (data << 8); | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r7(H) set to %04X\n", i8237_r7); | |
} else { /* low byte */ | |
i8237_rD++; | |
i8237_r7 = data & 0xFF; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r7(L) set to %04X\n", i8237_r7); | |
} | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_r8x(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { /* read status register */ | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r8 (status) read as %02X\n", i8237_r8); | |
return (i8237_r8); | |
} else { /* write command register */ | |
i8237_r9 = data & 0xFF; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_r9 (command) set to %02X\n", i8237_r9); | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_r9x(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { | |
sim_debug (DEBUG_reg, &i8237_dev, "Illegal read of i8237_r9\n"); | |
return 0; | |
} else { /* write request register */ | |
i8237_rC = data & 0xFF; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_rC (request) set to %02X\n", i8237_rC); | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_rAx(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { | |
sim_debug (DEBUG_reg, &i8237_dev, "Illegal read of i8237_rA\n"); | |
return 0; | |
} else { /* write single mask register */ | |
switch(data & 0x03) { | |
case 0: | |
if (data & 0x04) | |
i8237_rB |= 1; | |
else | |
i8237_rB &= ~1; | |
break; | |
case 1: | |
if (data & 0x04) | |
i8237_rB |= 2; | |
else | |
i8237_rB &= ~2; | |
break; | |
case 2: | |
if (data & 0x04) | |
i8237_rB |= 4; | |
else | |
i8237_rB &= ~4; | |
break; | |
case 3: | |
if (data & 0x04) | |
i8237_rB |= 8; | |
else | |
i8237_rB &= ~8; | |
break; | |
} | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_rB (mask) set to %02X\n", i8237_rB); | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_rBx(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { | |
sim_debug (DEBUG_reg, &i8237_dev, "Illegal read of i8237_rB\n"); | |
return 0; | |
} else { /* write mode register */ | |
i8237_rA = data & 0xFF; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_rA (mode) set to %02X\n", i8237_rA); | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_rCx(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { | |
sim_debug (DEBUG_reg, &i8237_dev, "Illegal read of i8237_rC\n"); | |
return 0; | |
} else { /* clear byte pointer FF */ | |
i8237_rD = 0; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_rD (FF) cleared\n"); | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_rDx(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { /* read temporary register */ | |
sim_debug (DEBUG_reg, &i8237_dev, "Illegal read of i8237_rD\n"); | |
return 0; | |
} else { /* master clear */ | |
i8237_reset1(); | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237 master clear\n"); | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_rEx(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { | |
sim_debug (DEBUG_reg, &i8237_dev, "Illegal read of i8237_rE\n"); | |
return 0; | |
} else { /* clear mask register */ | |
i8237_rB = 0; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_rB (mask) cleared\n"); | |
return 0; | |
} | |
} | |
return 0; | |
} | |
uint8 i8237_rFx(t_bool io, uint8 data) | |
{ | |
uint8 devnum; | |
if ((devnum = i8237_get_dn()) != 0xFF) { | |
if (io == 0) { | |
sim_debug (DEBUG_reg, &i8237_dev, "Illegal read of i8237_rF\n"); | |
return 0; | |
} else { /* write all mask register bits */ | |
i8237_rB = data & 0x0F; | |
sim_debug (DEBUG_reg, &i8237_dev, "i8237_rB (mask) set to %02X\n", i8237_rB); | |
return 0; | |
} | |
} | |
return 0; | |
} | |
/* end of i8237.c */ |