6502/EightBit
1
0
Fork 0
mirror of https://github.com/MoleskiCoder/EightBit.git synced 2024-12-23 15:29:24 +00:00
Code Issues Projects Releases Wiki Activity

Add LD instructions to the 6809 processor

Browse Source 
Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
This commit is contained in:
Adrian Conlon 2018-08-21 18:57:20 +01:00
parent 2a3b0a5291
commit a917fb0d4c
2 changed files with 60 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
MC6809/inc/mc6809.h
View File

@ -196,6 +196,8 @@ namespace EightBit {
uint8_t eor(uint8_t operand, uint8_t data);
void exg(uint8_t data);
uint8_t inc(uint8_t operand);
uint8_t ld(uint8_t data);
register16_t ld(register16_t data);
uint8_t neg(uint8_t operand);
register16_t m_d;

58
MC6809/src/mc6809.cpp
View File

@ -204,6 +204,38 @@ int EightBit::mc6809::executeUnprefixed(uint8_t opcode) {
case 0xad: addCycles(6); call(Address_indexed()); break; // JSR (JSR indexed)
case 0xbd: addCycles(7); call(Address_extended()); break; // JSR (JSR extended)
// LD
// LDA
case 0x86: addCycles(2); A() = ld(AM_immediate_byte()); break; // LD (LDA immediate)
case 0x96: addCycles(4); A() = ld(AM_direct_byte()); break; // LD (LDA direct)
case 0xa6: addCycles(4); A() = ld(AM_indexed_byte()); break; // LD (LDA indexed)
case 0xb6: addCycles(5); A() = ld(AM_extended_byte()); break; // LD (LDA extended)
// LDB
case 0xc6: addCycles(2); B() = ld(AM_immediate_byte()); break; // LD (LDB immediate)
case 0xd6: addCycles(4); B() = ld(AM_direct_byte()); break; // LD (LDB direct)
case 0xe6: addCycles(4); B() = ld(AM_indexed_byte()); break; // LD (LDB indexed)
case 0xf6: addCycles(5); B() = ld(AM_extended_byte()); break; // LD (LDB extended)
// LDD
case 0xcc: addCycles(3); D() = ld(AM_immediate_word()); break; // LD (LDD immediate)
case 0xdc: addCycles(5); D() = ld(AM_direct_word()); break; // LD (LDD direct)
case 0xec: addCycles(5); D() = ld(AM_indexed_word()); break; // LD (LDD indexed)
case 0xfc: addCycles(6); D() = ld(AM_extended_word()); break; // LD (LDD extended)
// LDU
case 0xce: addCycles(3); U() = ld(AM_immediate_word()); break; // LD (LDU immediate)
case 0xde: addCycles(5); U() = ld(AM_direct_word()); break; // LD (LDU direct)
case 0xee: addCycles(5); U() = ld(AM_indexed_word()); break; // LD (LDU indexed)
case 0xfe: addCycles(6); U() = ld(AM_extended_word()); break; // LD (LDU extended)
// LDX
case 0x8e: addCycles(3); X() = ld(AM_immediate_word()); break; // LD (LDX immediate)
case 0x9e: addCycles(5); X() = ld(AM_direct_word()); break; // LD (LDX direct)
case 0xae: addCycles(5); X() = ld(AM_indexed_word()); break; // LD (LDX indexed)
case 0xbe: addCycles(6); X() = ld(AM_extended_word()); break; // LD (LDX extended)
default:
UNREACHABLE;
}
@ -238,6 +270,20 @@ int EightBit::mc6809::execute10(uint8_t opcode) {
case 0xac: addCycles(7); cmp(Y(), AM_indexed_word()); break; // CMP (CMPY, indexed)
case 0xbc: addCycles(8); cmp(Y(), AM_extended_word()); break; // CMP (CMPY, extended)
// LD
// LDS
case 0xce: addCycles(4); S() = ld(AM_immediate_word()); break; // LD (LDS immediate)
case 0xde: addCycles(6); S() = ld(AM_direct_word()); break; // LD (LDS direct)
case 0xee: addCycles(6); S() = ld(AM_indexed_word()); break; // LD (LDS indexed)
case 0xfe: addCycles(7); S() = ld(AM_extended_word()); break; // LD (LDS extended)
// LDY
case 0x8e: addCycles(4); Y() = ld(AM_immediate_word()); break; // LD (LDY immediate)
case 0x9e: addCycles(6); Y() = ld(AM_direct_word()); break; // LD (LDY direct)
case 0xae: addCycles(6); Y() = ld(AM_indexed_word()); break; // LD (LDY indexed)
case 0xbe: addCycles(7); Y() = ld(AM_extended_word()); break; // LD (LDY extended)
default:
UNREACHABLE;
}
@ -593,3 +639,15 @@ uint8_t EightBit::mc6809::inc(uint8_t operand) {
adjustOverflow(operand, 1, result);
return result;
}
uint8_t EightBit::mc6809::ld(uint8_t data) {
clearFlag(CC(), VF);
adjustNZ(data);
return data;
}
EightBit::register16_t EightBit::mc6809::ld(register16_t data) {
clearFlag(CC(), VF);
adjustNZ(data.word);
return data;
}