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Emulator: Implement call opcodes

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Riyyi
2022-08-26 05:39:09 +02:00
parent 219520965c
commit d33837f118
1 changed files with 21 additions and 6 deletions
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src/cpu.cpp
+21 -6
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@@ -198,8 +198,12 @@ void CPU::update()
case 0xbe: cp(); break; case 0xbe: cp(); break;
case 0xbf: cp(); break; case 0xbf: cp(); break;
case 0xc3: jp16(); break; case 0xc3: jp16(); break;
case 0xc4: call(); break;
case 0xc6: addi8(); break; case 0xc6: addi8(); break;
case 0xcc: call(); break;
case 0xcd: call(); break; case 0xcd: call(); break;
case 0xd4: call(); break;
case 0xdc: call(); break;
case 0xe0: ldffi8(); break; case 0xe0: ldffi8(); break;
case 0xe2: ldr8(); break; case 0xe2: ldr8(); break;
case 0xe6: and8(); break; case 0xe6: and8(); break;
@@ -894,13 +898,17 @@ void CPU::ldr16()
void CPU::call() void CPU::call()
{ {
uint8_t opcode = pcRead(); auto function_call = [this](bool should_call) -> void {
switch (opcode) { // CALL cc,i16
case 0xcd: { // CALL a16
m_wait_cycles += 24;
// Note: the operand is read even when the condition is false
uint32_t data = pcRead16(); uint32_t data = pcRead16();
if (!should_call) {
m_wait_cycles += 12;
}
m_wait_cycles += 24;
// Push address of next 2 bytes in memory onto stack // Push address of next 2 bytes in memory onto stack
m_sp = (m_sp - 1) & 0xffff; m_sp = (m_sp - 1) & 0xffff;
write(m_sp, data >> 8); write(m_sp, data >> 8);
@@ -909,8 +917,15 @@ void CPU::call()
// Jump to this address // Jump to this address
m_pc = data; m_pc = data;
break; };
}
uint8_t opcode = pcRead();
switch (opcode) {
case 0xc4: /* CALL NZ,i16 */ function_call(!m_nf); break;
case 0xcc: /* CALL Z,i16 */ function_call(m_nf); break;
case 0xcd: /* CALL i16 */ function_call(true); break;
case 0xd4: /* CALL NC,i16 */ function_call(!m_cf); break;
case 0xdc: /* CALL C,i16 */ function_call(m_cf); break;
default: default:
VERIFY_NOT_REACHED(); VERIFY_NOT_REACHED();
} }