| /* 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 |
| 02 Write Load DMAC Channel 1 Base and Current Address Regsiters |
| Read Read DMAC Channel 1 Current Address Register |
| 03 Write Load DMAC Channel 1 Base and Current Word Count Registers |
| Read Read DMAC Channel 1 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 |
| |
| /* function prototypes */ |
| |
| t_stat i8237_svc(UNIT *uptr); |
| t_stat i8237_reset(DEVICE *dptr, uint16 base); |
| void i8237_reset1(int32 devnum); |
| 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[4]; // 8237 ch 0 address register |
| uint16 i8237_r1[4]; // 8237 ch 0 count register |
| uint16 i8237_r2[4]; // 8237 ch 1 address register |
| uint16 i8237_r3[4]; // 8237 ch 1 count register |
| uint16 i8237_r4[4]; // 8237 ch 2 address register |
| uint16 i8237_r5[4]; // 8237 ch 2 count register |
| uint16 i8237_r6[4]; // 8237 ch 3 address register |
| uint16 i8237_r7[4]; // 8237 ch 3 count register |
| uint8 i8237_r8[4]; // 8237 status register |
| uint8 i8237_r9[4]; // 8237 command register |
| uint8 i8237_rA[4]; // 8237 mode register |
| uint8 i8237_rB[4]; // 8237 mask register |
| uint8 i8237_rC[4]; // 8237 request register |
| uint8 i8237_rD[4]; // 8237 first/last ff |
| uint8 i8237_rE[4]; // 8237 |
| uint8 i8237_rF[4]; // 8237 |
| |
| /* i8237 physical register definitions */ |
| |
| uint16 i8237_sr[4]; // isbc-208 segment register |
| uint8 i8237_i[4]; // iSBC-208 interrupt register |
| uint8 i8237_a[4]; // 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[devnum], 16) }, |
| { HRDATA (CH0CNT, i8237_r1[devnum], 16) }, |
| { HRDATA (CH1ADR, i8237_r2[devnum], 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 = { |
| "I8237", //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", 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; |
| } |
| sim_printf(" 8237 Reset\n"); |
| sim_printf(" 8237: Registered at %03X\n", base); |
| 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); |
| 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(int32 devnum) |
| { |
| int32 i; |
| UNIT *uptr; |
| |
| uptr = i8237_dev[devnum].units; |
| if (uptr->capac == 0) { /* if not configured */ |
| 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[devnum], i8237_unit[devnum].wait); |
| } |
| i8237_r8[devnum] = 0; /* status */ |
| i8237_r9[devnum] = 0; /* command */ |
| i8237_rB[devnum] = 0x0F; /* mask */ |
| i8237_rC[devnum] = 0; /* request */ |
| i8237_rD[devnum] = 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[%d](H) read as %04X\n", devnum, i8237_r0[devnum]); |
| return (i8237_r0[devnum] >> 8); |
| } else { /* low byte */ |
| i8237_rD++; |
| sim_debug (DEBUG_reg, &i8237_dev, "i8237_r0[%d](L) read as %04X\n", devnum, i8237_r0[devnum]); |
| return (i8237_r0[devnum] & 0xFF); |
| } |
| } else { /* write base & current address CH 0 */ |
| if (i8237_rD) { /* high byte */ |
| i8237_rD = 0; |
| i8237_r0[devnum] |= (data << 8); |
| sim_debug (DEBUG_reg, &i8237_dev, "i8237_r0[%d](H) set to %04X\n", devnum, i8237_r0[devnum]); |
| } else { /* low byte */ |
| i8237_rD++; |
| i8237_r0[devnum] = data & 0xFF; |
| sim_debug (DEBUG_reg, &i8237_dev, "i8237_r0[%d](L) set to %04X\n"devnum, , i8237_r0[devnum]); |
| } |
| 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[%d](H) read as %04X\n", devnum, i8237_r1[devnum]); |
| return (i8237_r1[devnum][devnum] >> 8); |
| } else { /* low byte */ |
| i8237_rD++; |
| sim_debug (DEBUG_reg, &i8237_dev, "i8237_r1[%d](L) read as %04X\n", devnum, i8237_r1[devnum]); |
| return (i8237_r1[devnum] & 0xFF); |
| } |
| } else { /* write base & current address CH 0 */ |
| if (i8237_rD) { /* high byte */ |
| i8237_rD = 0; |
| i8237_r1[devnum] |= (data << 8); |
| sim_debug (DEBUG_reg, &i8237_dev, "i8237_r1[%d](H) set to %04X\n", devnum, i8237_r1[devnum]); |
| } else { /* low byte */ |
| i8237_rD++; |
| i8237_r1[devnum] = data & 0xFF; |
| sim_debug (DEBUG_reg, &i8237_dev, "i8237_r1[%d](L) set to %04X\n", devnum, i8237_r1[devnum]); |
| } |
| 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[%d](H) read as %04X\n", devnum, i8237_r2[devnum]); |
| return (i8237_r2[devnum] >> 8); |
| } else { /* low byte */ |
| i8237_rD++; |
| sim_debug (DEBUG_reg, &i8237_dev, "i8237_r2[%d](L) read as %04X\n", devnum, i8237_r2[devnum]); |
| return (i8237_r2[devnum] & 0xFF); |
| } |
| } else { /* write base & current address CH 1 */ |
| if (i8237_rD) { /* high byte */ |
| i8237_rD = 0; |
| i8237_r2[devnum] |= (data << 8); |
| sim_debug (DEBUG_reg, &i8237_dev, "i8237_r2[%d](H) set to %04X\n", devnum, i8237_r2[devnum]); |
| } else { /* low byte */ |
| i8237_rD++; |
| i8237_r2[devnum] = data & 0xFF; |
| sim_debug (DEBUG_reg, &i8237_dev, "i8237_r2[%d](L) set to %04X\n", devnum, i8237_r2[devnum]); |
| } |
| 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; |
| } |
| } |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| /* end of i8237.c */ |