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CPU: Added support for reading into registers from indirect memory access with register

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(Tim) Efthimis Kritikos 2024-02-14 14:03:03 +00:00
parent d643dc3e55
commit 35588a07c8
3 changed files with 62 additions and 10 deletions
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40
assembly.c
View File

@ -456,6 +456,46 @@ int64_t assemble_line(char *line, struct assembler_context_t *assembler_context)
return -2;
}else
return -2;
}else if(line[x]=='('){
while(line[x]==' ')x++;
x++;
if(line[x]=='%'){
x++;
if(line[x]=='R'){
x++;
if(line[x]>='0'&&line[x]<='7'){
r0=line[x]-'0';
x++;
while(line[x]==' ')x++;
if(line[x]==')'){
x++;
while(line[x]==' ')x++;
if(line[x]==','){
x++;
while(line[x]==' ')x++;
if(line[x]=='%'){
x++;
if(line[x]=='R'){
x++;
if(line[x]>='0'&&line[x]<='7'){
r1=line[x]-'0';
return 0x20090000|(r0&0xFF)<<8|(r1&0xFF);
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else
return -2;
}else if(strncmp(line,"HALT ",5)==0||strncmp(line,"HALT\0",5)==0){

14
cpu.c
View File

@ -59,12 +59,12 @@ int decode(struct simdata_t *simdata){
simdata->exec_data->out_op->data=simdata->decode_data->in_bytecode&0x00FFFFFF;
simdata->exec_data->EXEC_ACTION=(opcode&0x10)?CALL:JUMP;
break;
case 0x0F:
case 0x0F:/* load SP */
simdata->exec_data->EXEC_ACTION=MOVE;
simdata->exec_data->in_op1->OP_ADDR=IMMEDIATE;
simdata->exec_data->in_op1->data=simdata->decode_data->in_bytecode&0x00FFFFFF;
simdata->exec_data->out_op->OP_ADDR=REGISTER;
simdata->exec_data->out_op->data=0;
simdata->exec_data->out_op->data=0xFF;
break;
case 0x10:
simdata->exec_data->EXEC_ACTION=RET;
@ -311,17 +311,25 @@ int exec(struct simdata_t *simdata){
simdata->registers->GPR[simdata->exec_data->in_op1->data])<<16);
break;
case REGISTER: /* This is for special registers like the SP which is 24bits long */
if(simdata->exec_data->out_op->data==0xFF){
if(simdata->exec_data->in_op1->OP_ADDR==IMMEDIATE){
if( (simdata->exec_data->in_op1->data&0xFF000000) == 0 )
simdata->registers->SP=simdata->exec_data->in_op1->data;
else
return 2;
}else{
}else if( simdata->exec_data->in_op1->OP_ADDR==REGISTER ){ /*for completeion, not valid ( yet )*/
if( (simdata->registers->GPR[simdata->exec_data->in_op1->data]&0xFF000000) == 0 )
simdata->registers->SP=simdata->registers->GPR[simdata->exec_data->in_op1->data];
else
return 2;
}
}else if(simdata->exec_data->in_op1->OP_ADDR==REGISTER_IND){
if( (simdata->registers->GPR[simdata->exec_data->in_op1->data]&0xFF000000) == 0 )
simdata->registers->GPR[simdata->exec_data->out_op->data]=*(uint32_t*)(simdata->RAM+simdata->registers->GPR[simdata->exec_data->in_op1->data]);
else
return 2;
}else
return 1;
break;
case REGISTER_IND:
if(simdata->exec_data->in_op1->OP_ADDR==REGISTER){

4
test.asm
View File

@ -48,6 +48,10 @@ MOV %R1,(%R0)
MOV $0xcccd,%R1l
MOV $0x3f4c,%R1h
MOV %R1,(%R0)
MOV $0x00D0,%R0l
MOV $0x0000,%R0h
MOV %R1,(%R0)
MOV (%R0),%R5
HALT
:TR_LOW
DDW $0xDEADBEEF