6502/emu6502
1
0
Fork 0
mirror of https://github.com/jborza/emu6502.git synced 2024-11-28 23:49:24 +00:00
Code Issues Projects Releases Wiki Activity

ROL implementation

Browse Source
This commit is contained in:
jborza 2019-04-19 11:55:17 +02:00
parent 2d86c1df28
commit a4a56ddc9f
1 changed files with 26 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
cpu.c
View File

@ -194,10 +194,30 @@ void LSR_A(State6502* state) {
void LSR_MEM(State6502* state, word address) {
byte operand = state->memory[address];
state->memory[address] = operand;
state->memory[address] = lsr(state, operand);
}
byte ror(State6502* state, byte operand) {
//TODO implement
}
byte rol(State6502* state, byte operand) {
word result_word = (operand << 1) | state->flags.c;
state->flags.c = result_word > 0xFF;
byte result = result_word & 0xFF;
set_NV_flags(state, result);
return result;
}
void ROL_A(State6502* state) {
state->a = rol(state, state->a);
}
void ROL_MEM(State6502* state, word address) {
byte operand = state->memory[address];
state->memory[address] = rol(state, operand);
}
word pop_word(State6502 * state) {
byte low = pop_byte(state);
byte high = pop_byte(state);
@ -444,11 +464,11 @@ int emulate_6502_op(State6502 * state) {
case ORA_ABSY: ORA(state, get_byte_absolute_y(state)); break;
case ORA_INDX: ORA(state, get_byte_indirect_x(state)); break;
case ORA_INDY: ORA(state, get_byte_indirect_y(state)); break;
case ROL_ACC: unimplemented_instruction(state); break;
case ROL_ZP: unimplemented_instruction(state); break;
case ROL_ZPX: unimplemented_instruction(state); break;
case ROL_ABS: unimplemented_instruction(state); break;
case ROL_ABSX: unimplemented_instruction(state); break;
case ROL_ACC: ROL_A(state); break;
case ROL_ZP: ROL_MEM(state, get_address_zero_page(state)); break;
case ROL_ZPX: ROL_MEM(state, get_address_zero_page_x(state)); break;
case ROL_ABS: ROL_MEM(state, get_address_absolute(state)); break;
case ROL_ABSX: ROL_MEM(state, get_address_absolute_x(state)); break;
case ROR_ACC: unimplemented_instruction(state); break;
case ROR_ZP: unimplemented_instruction(state); break;
case ROR_ZPX: unimplemented_instruction(state); break;