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Add OR instruction to the 6809 processor

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Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
This commit is contained in:
Adrian Conlon 2018-08-21 23:07:22 +01:00
parent 06f4300c38
commit 551c26bb3c
2 changed files with 25 additions and 1 deletions
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1
MC6809/inc/mc6809.h
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@ -215,6 +215,7 @@ namespace EightBit {
uint8_t lsr(uint8_t operand);
register16_t mul(uint8_t first, uint8_t second);
uint8_t neg(uint8_t operand);
uint8_t orr(uint8_t operand, uint8_t data);
register16_t m_d;
register16_t m_x;

25
MC6809/src/mc6809.cpp
View File

@ -89,7 +89,7 @@ int EightBit::mc6809::executeUnprefixed(uint8_t opcode) {
case 0xe4: addCycles(4); B() = andr(B(), AM_indexed_byte()); break; // AND (ANDB indexed)
case 0xf4: addCycles(5); B() = andr(B(), AM_extended_byte()); break; // AND (ANDB extended)
case 0x1c: addCycles(3); CC() = andr(CC(), AM_immediate_byte()); break; // AND (ANDCC immediate)
case 0x1c: addCycles(3); CC() &= AM_immediate_byte(); break; // AND (ANDCC immediate)
// ASL/LSL
case 0x08: addCycles(6); BUS().write(asl(AM_direct_byte())); break; // ASL (direct)
@ -255,6 +255,23 @@ int EightBit::mc6809::executeUnprefixed(uint8_t opcode) {
// NOP
case 0x12: addCycles(2); break; // NOP (inherent)
// OR
// ORA
case 0x8a: addCycles(3); A() = orr(A(), AM_immediate_byte()); break; // OR (ORA immediate)
case 0x9a: addCycles(3); A() = orr(A(), AM_direct_byte()); break; // OR (ORA direct)
case 0xaa: addCycles(3); A() = orr(A(), AM_indexed_byte()); break; // OR (ORA indexed)
case 0xba: addCycles(3); A() = orr(A(), AM_extended_byte()); break; // OR (ORA extended)
// ORB
case 0xca: addCycles(3); A() = orr(A(), AM_immediate_byte()); break; // OR (ORB immediate)
case 0xda: addCycles(3); A() = orr(A(), AM_direct_byte()); break; // OR (ORB direct)
case 0xea: addCycles(3); A() = orr(A(), AM_indexed_byte()); break; // OR (ORB indexed)
case 0xfa: addCycles(3); A() = orr(A(), AM_extended_byte()); break; // OR (ORB extended)
// ORCC
case 0x1a: addCycles(3); CC() |= AM_immediate_byte(); break; // OR (ORCC immediate)
default:
UNREACHABLE;
}
@ -675,3 +692,9 @@ uint8_t EightBit::mc6809::neg(uint8_t operand) {
adjustCarry(result);
return operand;
}
uint8_t EightBit::mc6809::orr(uint8_t operand, uint8_t data) {
clearFlag(CC(), VF);
adjustNZ(operand |= data);
return operand;
}