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add lea register (load effective address)

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Erick
2022-02-04 12:22:53 +01:00
parent 877b27a224
commit 0f3f1a047b
1 changed files with 9 additions and 3 deletions
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tyvm.c
+9 -3
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@@ -51,7 +51,7 @@ uint16_t memory[UINT16_MAX];
uint16_t reg[RG_COUNT]; uint16_t reg[RG_COUNT];
/* Creating instruction set opcodes */ /* Creating instruction set opcodes */
enum opcodes { // [name, value] enum opcodes { // [name, 8-bit value]
OP_BR = 0, // branch, 0000 OP_BR = 0, // branch, 0000
OP_ADD, // add, 0001 OP_ADD, // add, 0001
OP_LD, // load, 0010 OP_LD, // load, 0010
@@ -66,7 +66,7 @@ enum opcodes { // [name, value]
OP_STI, // indirect store, 1011 OP_STI, // indirect store, 1011
OP_JMP, // jump, 1100 OP_JMP, // jump, 1100
OP_RES, // reserved opcode, OP_RES, // reserved opcode,
OP_LEA, // load effective address, OP_LEA, // load effective address, 1110
OP_TRAP, // execute trap, OP_TRAP, // execute trap,
}; };
@@ -245,7 +245,13 @@ int main(int argc, const char* argv[]) {
break; break;
case OP_LEA: case OP_LEA:
//{LEA}; uint16_t dr = (instr >> 9) & 0x7;
uint16_t PCoffset9 = sign_extend(instr & 0x1FF, 9);
reg[dr] = reg[RG_PC] + PCoffset9;
update_flags(dr);
break; break;
case OP_TRAP: case OP_TRAP:
//{TRAP}; //{TRAP};