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implemented the remaining branching instructions

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This commit is contained in:
jborza 2019-04-27 13:02:04 +02:00
parent b4e260d3d4
commit 4ad8a47739
2 changed files with 52 additions and 10 deletions
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56
cpu.c
View File

@ -285,6 +285,48 @@ void BEQ(State6502* state) {
state->pc = address;
}
void BNE(State6502* state) {
word address = get_address_relative(state);
if (!state->flags.z)
state->pc = address;
}
void BCC(State6502* state) {
word address = get_address_relative(state);
if (!state->flags.c)
state->pc = address;
}
void BCS(State6502* state) {
word address = get_address_relative(state);
if (state->flags.c)
state->pc = address;
}
void BMI(State6502* state) {
word address = get_address_relative(state);
if (state->flags.n)
state->pc = address;
}
void BPL(State6502* state) {
word address = get_address_relative(state);
if (!state->flags.n)
state->pc = address;
}
void BVS(State6502* state) {
word address = get_address_relative(state);
if (state->flags.v)
state->pc = address;
}
void BVC(State6502* state) {
word address = get_address_relative(state);
if (!state->flags.v)
state->pc = address;
}
word pop_word(State6502 * state) {
byte low = pop_byte(state);
byte high = pop_byte(state);
@ -316,14 +358,14 @@ int emulate_6502_op(State6502 * state) {
case ASL_ZPX: ASL_MEM(state, get_address_zero_page_x(state)); break;
case ASL_ABS: ASL_MEM(state, get_address_absolute(state)); break;
case ASL_ABSX: ASL_MEM(state, get_address_absolute_x(state)); break;
case BCC_REL: unimplemented_instruction(state); break;
case BCS_REL: unimplemented_instruction(state); break;
case BCC_REL: BCC(state); break;
case BCS_REL: BCS(state); break;
case BEQ_REL: BEQ(state); break;
case BMI_REL: unimplemented_instruction(state); break;
case BNE_REL: unimplemented_instruction(state); break;
case BPL_REL: unimplemented_instruction(state); break;
case BVC_REL: unimplemented_instruction(state); break;
case BVS_REL: unimplemented_instruction(state); break;
case BMI_REL: BMI(state); break;
case BNE_REL: BNE(state); break;
case BPL_REL: BPL(state); break;
case BVC_REL: BVC(state); break;
case BVS_REL: BVS(state); break;
case BIT_ZP: BIT(state, get_byte_zero_page(state)); break;
case BIT_ABS: BIT(state, get_byte_absolute(state)); break;
case BRK: state->running = 0;

6
test6502.c
View File

@ -2266,7 +2266,7 @@ void test_BRK() {
void test_branch(byte opcode, byte n, byte v, byte z, byte c, word expected_pc){
State6502 state = create_blank_state();
state.flags.n = n;
state.flags.v = n;
state.flags.v = v;
state.flags.z = z;
state.flags.c = c;
char program[] = { opcode, 0xFE };
@ -2284,8 +2284,8 @@ void test_branching_multiple() {
test_branch(BNE_REL, /*N*/ 0, /*V*/ 0, /*Z*/ 1, /*C*/ 0, /*EXP_PC*/0x02);
test_branch(BCC_REL, /*N*/ 0, /*V*/ 0, /*Z*/ 0, /*C*/ 0, /*EXP_PC*/0x00);
test_branch(BCC_REL, /*N*/ 0, /*V*/ 0, /*Z*/ 0, /*C*/ 1, /*EXP_PC*/0x02);
test_branch(BCS_REL, /*N*/ 0, /*V*/ 0, /*Z*/ 0, /*C*/ 0, /*EXP_PC*/0x00);
test_branch(BCS_REL, /*N*/ 0, /*V*/ 0, /*Z*/ 0, /*C*/ 1, /*EXP_PC*/0x02);
test_branch(BCS_REL, /*N*/ 0, /*V*/ 0, /*Z*/ 0, /*C*/ 1, /*EXP_PC*/0x00);
test_branch(BCS_REL, /*N*/ 0, /*V*/ 0, /*Z*/ 0, /*C*/ 0, /*EXP_PC*/0x02);
test_branch(BMI_REL, /*N*/ 1, /*V*/ 0, /*Z*/ 0, /*C*/ 0, /*EXP_PC*/0x00);
test_branch(BMI_REL, /*N*/ 0, /*V*/ 0, /*Z*/ 0, /*C*/ 0, /*EXP_PC*/0x02);
test_branch(BPL_REL, /*N*/ 0, /*V*/ 0, /*Z*/ 0, /*C*/ 0, /*EXP_PC*/0x00);