jb302@39: #include <stdio.h>
jb302@39: #include <reg52.h>
jb302@39: 
jb302@39: #define MAIN
jb302@39: #include "mem.h"
jb302@39: #include "iset.h"
jb302@39: 
jb302@39: /* fill instruction table 
jb302@39:  * MCS-51 - this needs to be stored in code memory */
jb302@39: 
jb302@39: FUNCTION_TABLE const code iset = {
jb302@39:     NOP, NOP, NOP, NOP, NOP, NOP, NOP, NOP,
jb302@39:     SET, CLR, SET, CLR, SET, CLR, CPL, CPL,
jb302@39:     XCSD, SFA, LAF, MOV, MOV, MOV, MOV, MOV,
jb302@39:     MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
jb302@39:     MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
jb302@39:     MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
jb302@39:     MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
jb302@39:     MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
jb302@39:     MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
jb302@39:     MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
jb302@39:     MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
jb302@39:     MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
jb302@39:     MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
jb302@39:     MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
jb302@39:     MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
jb302@39:     MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
jb302@39:     ANL, ANL, ANL, ANL, ANL, ANL, ANL, ANL,
jb302@39:     ORL, ORL, ORL, ORL, ORL, ORL, ORL, ORL,
jb302@39:     XRL, XRL, XRL, XRL, XRL, XRL, XRL, XRL,
jb302@39:     RL, RLC, RR, RRC, INC, DEC, INC, DEC,
jb302@39:     ADD, ADD, ADD, ADD, ADD, ADD, ADD, ADD,
jb302@39:     ADDC, ADDC, ADDC, ADDC, ADDC, ADDC, ADDC, ADDC,
jb302@39:     SUB, SUB, SUB, SUB, SUB, SUB, SUB, SUB,
jb302@39:     SUBB, SUBB, SUBB, SUBB, SUBB, SUBB, SUBB, SUBB,
jb302@39:     PJMP, PJMP, PJMP, PJMP, PJMP, PJMP, PJMP, PJMP,
jb302@39:     PCALL, PCALL, PCALL, PCALL, PCALL, PCALL, PCALL, PCALL,
jb302@39:     DJNZ, DJNZ, DJNZ, DJNZ, CJNE, CJNE, CJNE, CJNE,
jb302@39:     LJMP, LCALL, RET, RETI, SJMP, JMP, JMP, CJNE,
jb302@39:     JZ, JNZ, JC, JNC, JPO, JPE, JS, JNS,
jb302@39:     PUSH, PUSH, PUSH, PUSH, PUSH, PUSH, PUSH, PUSH,
jb302@39:     POP, POP, POP, POP, POP, POP, POP, POP,
jb302@39:     MUL, DIV, DA, NOP, IN, OUT, INT, HLT
jb302@39: }; 
jb302@39: 
jb302@39: BYTE pause;     /* becomes 1 when we hit a break point in run mode */
jb302@39: BYTE free_run;  /* free run if not 0 */
jb302@39: BYTE pause;     /* pause flag */
jb302@39: WIDE addrc;        /* address counter */
jb302@39: BYTE args[4];   /* dbg args */
jb302@39: 
jb302@39: WIDE bp[8] = {  0xFFFF,
jb302@39:                 0xFFFF,
jb302@39:                 0xFFFF,
jb302@39:                 0xFFFF,
jb302@39:                 0xFFFF,
jb302@39:                 0xFFFF,
jb302@39:                 0xFFFF,
jb302@39:                 0xFFFF
jb302@39: };
jb302@39: 
jb302@39: 
jb302@39: void
jb302@39: snd(BYTE c) {
jb302@39: putchar(c);
jb302@39: }
jb302@39: 
jb302@39: BYTE
jb302@39: rcv(void) {
jb302@39:     return getchar();
jb302@39: }
jb302@39: 
jb302@39: void
jb302@39: step(void) {
jb302@39:     IR = fetch();
jb302@39:     iset.ops[IR]();  
jb302@39: }
jb302@39: 
jb302@39: void
jb302@39: run(void) {
jb302@39:     while (pause != 1) {
jb302@39:         step();
jb302@39:         for (addrc = 0; addrc < 8; addrc++) {
jb302@39:             if (bp[addrc] == get_wide(PC)) {
jb302@39:                 pause = 1;
jb302@39:             }
jb302@39:         }
jb302@39:     }
jb302@39: }
jb302@39: 
jb302@39: void controller() {
jb302@39:     if (free_run == 0) {
jb302@39:             switch (rcv()) {
jb302@39: 
jb302@39:                 /* step */
jb302@39:                 case 0x00:
jb302@39:                     step();
jb302@39:                     break;
jb302@39: 
jb302@39:                 /* run for length steps*/
jb302@39:                 case 0x01:
jb302@39:                     run();
jb302@39:                     break;
jb302@39: 
jb302@39:                 /* set reg */
jb302@39:                 case 0x02:
jb302@39:                     args[0] = rcv(); /* reg */
jb302@39:                     args[1] = rcv(); /* val */
jb302@39:                     regs[args[0]] = args[1];
jb302@39:                     break;
jb302@39: 
jb302@39:                 /* get reg */
jb302@39:                 case 0x03:
jb302@39:                     args[0] = rcv(); /* reg */
jb302@39:                     snd(regs[args[0]]);
jb302@39:                     break;
jb302@39: 
jb302@39:                 /* set flag */
jb302@39:                 case 0x04:
jb302@39:                     args[0] = rcv(); /* flag */
jb302@39:                     args[1] = rcv(); /* on? */
jb302@39:                     set_flag(args[0], args[1]);
jb302@39:                     break;
jb302@39:         
jb302@39:                 /* get flag */
jb302@39:                 case 0x05:
jb302@39:                     args[0] = rcv(); /* flag */
jb302@39:                     snd(get_flag(args[0]));
jb302@39:                     break;
jb302@39: 
jb302@39:                 /* write mem block */
jb302@39:                 case 0x06:
jb302@39:                     args[0] = rcv(); /* addr high */
jb302@39:                     args[1] = rcv(); /* addr low */
jb302@39:                     args[2] = rcv(); /* length high */
jb302@39:                     args[3] = rcv(); /* length low */
jb302@39:                     tmpw = MWIDE(args[0], args[1]);         
jb302@39:                     for (addrc = tmpw; addrc < tmpw + MWIDE(args[2], args[3]); addrc++) { 
jb302@39:                         if (addrc >= 0xFFFF) {
jb302@39:                             break;
jb302@39:                         }
jb302@39:                         mem[addrc] = rcv();
jb302@39:                     }
jb302@39:                     break;
jb302@39: 
jb302@39:                 /* read mem block */
jb302@39:                 case 0x07:
jb302@39:                     args[0] = rcv(); /* addr high */
jb302@39:                     args[1] = rcv(); /* addr low */
jb302@39:                     args[2] = rcv(); /* length high */
jb302@39:                     args[3] = rcv(); /* length low */
jb302@39:                     tmpw = MWIDE(args[0], args[1]);         
jb302@39:                     for (addrc = tmpw; addrc < tmpw + MWIDE(args[2], args[3]); addrc++) { 
jb302@39:                         if (addrc >= 0xFFFF) {
jb302@39:                             break;
jb302@39:                         }
jb302@39:                         snd(mem[addrc]);
jb302@39:                     }
jb302@39:                     break;
jb302@39: 
jb302@39:                 /* get A */
jb302@39:                 case 0x08:
jb302@39:                     snd(A);
jb302@39:                     break;
jb302@39:                 
jb302@39:                 /* get flags */
jb302@39:                 case 0x09:
jb302@39:                     snd(flags);
jb302@39:                     break;
jb302@39:                 
jb302@39:                 /* get instruction register */
jb302@39:                 case 0x0A:
jb302@39:                     snd(IR);
jb302@39:                     break;
jb302@39:                
jb302@39: 		/* run for length */
jb302@39:                 case 0x0B:
jb302@39:                     args[0] = rcv(); /* length high */
jb302@39:                     args[1] = rcv(); /* length low */
jb302@39:                     for (tmpw = 0 ; tmpw < MWIDE(args[0], args[1]) ; tmpw++) {
jb302@39:                         step();
jb302@39:                     }
jb302@39:                     break;
jb302@39: 
jb302@39:                 case 0x0C:
jb302@39:                     free_run = 1;
jb302@39:                     break;
jb302@39:                 
jb302@39:                 /* set break point */
jb302@39:                 case 0x0D:
jb302@39:                     args[0] = rcv(); /* bp index */
jb302@39:                     args[1] = rcv(); /* address high */
jb302@39:                     args[2] = rcv(); /* address low */
jb302@39:                     if (args[0] > 7) {
jb302@39:                         break;
jb302@39:                     }
jb302@39:                     bp[args[0]] = MWIDE(args[1], args[2]);
jb302@39:                     break;
jb302@39:                 
jb302@39:                 /* test cmd */
jb302@39:                 case 0x54:
jb302@39:                     snd('A');
jb302@39:                     break;
jb302@39:            }
jb302@39:         }
jb302@39:     else {
jb302@39:         step();
jb302@39:     }
jb302@39: }
jb302@39: 
jb302@39: void 
jb302@39: main(void) {
jb302@39:      /* serial set up
jb302@39:      * SCON - mode 1, 8-bit UART, enable rcvr
jb302@39:      * TMOD - timer 1, mode 2, 8-bit reload
jb302@39:      * TH1 - reload value for 1200 baud @ 12MHz
jb302@39:      * TR1 - timer 1 run
jb302@39:      * TI - set TI to send first char of UART */
jb302@39:     /* dont go into free run on restart */
jb302@39:     free_run = 0;
jb302@39:     SCON  = 0x50;
jb302@39:     TMOD |= 0x20;
jb302@39:     TH1   = 0xE8;
jb302@39:     TR1   = 1;
jb302@39:     TI    = 1;
jb302@39:     for (;;) {
jb302@39:         controller();
jb302@39:     }
jb302@39: }
jb302@39: