Category : Assembly Language Source Code
Archive   : CUG292.ZIP
Filename : M04MCH.C

 
Output of file : M04MCH.C contained in archive : CUG292.ZIP

/* m04mch.c */

/*
* (C) Copyright 1989,1990
* All Rights Reserved
*
* Alan R. Baldwin
* 721 Berkeley St.
* Kent, Ohio 44240
*/

#include
#include
#include "asm.h"
#include "m6804.h"

/*
* Process a machine op.
*/
VOID
machine(mp)
struct mne *mp;
{
register op, t1, t2, type;
struct expr e1, e2, e3;
struct area *espa;
int c, v1, v2, v3;
char id[NCPS];

op = mp->m_valu;
type = mp->m_type;
switch (type) {

case S_SDP:
e1.e_mode = 0;
e1.e_flag = 0;
e1.e_addr = 0;
e1.e_base.e_ap = NULL;
espa = NULL;
if (more()) {
expr(&e1, 0);
if (e1.e_flag == 0 && e1.e_base.e_ap == NULL) {
if (e1.e_addr) {
err('b');
}
}
if ((c = getnb()) == ',') {
getid(id, -1);
espa = alookup(id);
if (espa == NULL) {
err('u');
}
} else {
unget(c);
}
}
if (espa) {
outdp(espa, &e1);
} else {
outdp(dot.s_area, &e1);
}
lmode = SLIST;
break;

case S_INH:
outab(op);
break;

case S_BRA:
expr(&e1, 0);
v1 = e1.e_addr - dot.s_addr - 1;
if ((v1 < -16) || (v1 > 15))
aerr();
if (e1.e_base.e_ap != dot.s_area)
rerr();
outab(op | v1&0x1F);
break;

case S_TYP1:
expr(&e1, 0);
v1 = e1.e_addr;
if ((v1 < -4096) || (v1 > 4095))
aerr();
e1.e_addr += op;
outrw(&e1, 0);
break;

case S_TYP2:
case S_TYP3:
t1 = addr(&e1);
if (type == S_TYP3 & t1 == S_IMMED) {
outab(op|0x08);
outrb(&e1, 0);
break;
}
if (t1 == S_DIR) {
v1 = e1.e_addr;
if ((e1.e_base.e_ap == NULL) &
v1 >= 0x80 & v1 <= 0x83) {
v1 &= 0x03;
if (op == 0xE0) {
outab(0xAC | v1);
break;
}
if (op == 0xE1) {
outab(0xBC | v1);
break;
}
if (op == 0xE6) {
outab(0xA8 | v1);
break;
}
if (op == 0xE7) {
outab(0xB8 | v1);
break;
}
}
outab(op|0x18);
outrb(&e1, R_PAG0);
break;
}
if (t1 == S_IX) {
outab(op);
break;
}
if (t1 == S_IY) {
outab(op|0x10);
break;
}
aerr();
break;

case S_CLR:
outab(0xB0);
outab(op);
outab(0x00);
break;

case S_LD:
t1 = addr(&e1);
if (t1 == S_IMMED) {
outab(0xB0);
outab(op);
outrb(&e1, 0);
break;
}
aerr();
break;

case S_MVI:
t1 = addr(&e1);
if (t1 != S_DIR)
aerr();
comma();
t2 = addr(&e2);
if (t2 != S_IMMED)
aerr();
outab(op);
outrb(&e1, 0);
outrb(&e2, 0);
break;

case S_APOST:
outab(op);
outab(0xFF);
break;

case S_BPM:
case S_BXPM:
case S_BYPM:
expr(&e2, 0);
outab(op);
if (type == S_BPM)
v1 = 0xFF;
if (type == S_BXPM)
v1 = 0x80;
if (type == S_BYPM)
v1 = 0x81;
outab(v1);
if (e2.e_base.e_ap == NULL || e2.e_base.e_ap == dot.s_area) {
v2 = e2.e_addr - dot.s_addr - 1;
if ((v2 < -128) || (v2 > 127))
aerr();
outab(v2);
} else {
outrb(&e2, R_PCR);
}
if (e2.e_mode != S_USER)
rerr();
break;

case S_BTB:
case S_BSC:
t1 = addr(&e1);
if (t1 != S_IMMED || e1.e_addr & ~0x07)
aerr();
comma();
t2 = addr(&e2);
if (t2 != S_DIR)
aerr();
if (type == S_BTB) {
comma();
expr(&e3, 0);
}
outab(op + (e1.e_addr & 0x07));
outrb(&e2, R_USGN);
if (type == S_BTB) {
if (e3.e_base.e_ap == NULL || e3.e_base.e_ap == dot.s_area) {
v3 = e3.e_addr - dot.s_addr - 1;
if ((v3 < -128) || (v3 > 127))
aerr();
outab(v3);
} else {
outrb(&e3, R_PCR);
}
if (e3.e_mode != S_USER)
rerr();
}
break;

default:
err('o');
}
}


/*
* The next character must be a
* comma.
*/
VOID
comma()
{
if (getnb() != ',')
qerr();
}

/*
* Machine specific initialization.
*/
VOID
minit()
{
}