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ADD instruction added to the 6809 implementation

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Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
This commit is contained in:
Adrian Conlon 2018-08-19 12:58:44 +01:00
parent cca7453e35
commit 33fbad7132
2 changed files with 76 additions and 23 deletions
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14
MC6809/inc/mc6809.h
View File

@ -96,14 +96,20 @@ namespace EightBit {
void Address_extended(); void Address_extended();
// Addressing mode readers // Addressing mode readers
uint8_t AM_immediate(); uint8_t AM_immediate_byte();
uint8_t AM_direct(); uint8_t AM_direct_byte();
uint8_t AM_indexed(); uint8_t AM_indexed_byte();
uint8_t AM_extended(); uint8_t AM_extended_byte();
register16_t AM_immediate_word();
register16_t AM_direct_word();
register16_t AM_indexed_word();
register16_t AM_extended_word();
void abx(); void abx();
uint8_t adc(uint8_t operand, uint8_t data); uint8_t adc(uint8_t operand, uint8_t data);
uint8_t add(uint8_t operand, uint8_t data, int carry = 0); uint8_t add(uint8_t operand, uint8_t data, int carry = 0);
register16_t add(register16_t operand, register16_t data);
uint8_t neg(uint8_t operand); uint8_t neg(uint8_t operand);
register16_t m_d; register16_t m_d;

85
MC6809/src/mc6809.cpp
View File

@ -31,24 +31,41 @@ int EightBit::mc6809::execute(uint8_t cell) {
switch (cell) { switch (cell) {
// ABX // ABX
case 0x3a: addCycles(3); abx(); break; // ABX (inherent) case 0x3a: addCycles(3); abx(); break; // ABX (inherent)
// ADC // ADC
case 0x89: addCycles(2); A() = adc(A(), AM_immediate()); break; // ADC (ADCA, immediate) case 0x89: addCycles(2); A() = adc(A(), AM_immediate_byte()); break; // ADC (ADCA, immediate)
case 0x99: addCycles(4); A() = adc(A(), AM_direct()); break; // ADC (ADCA, direct) case 0x99: addCycles(4); A() = adc(A(), AM_direct_byte()); break; // ADC (ADCA, direct)
case 0xA9: addCycles(4); A() = adc(A(), AM_indexed()); break; // ADC (ADCA, indexed) case 0xA9: addCycles(4); A() = adc(A(), AM_indexed_byte()); break; // ADC (ADCA, indexed)
case 0xB9: addCycles(4); A() = adc(A(), AM_extended()); break; // ADC (ADCA, extended) case 0xB9: addCycles(4); A() = adc(A(), AM_extended_byte()); break; // ADC (ADCA, extended)
case 0xC9: addCycles(2); B() = adc(B(), AM_immediate()); break; // ADC (ADCB, immediate)
case 0xD9: addCycles(4); B() = adc(B(), AM_direct()); break; // ADC (ADCB, direct) case 0xC9: addCycles(2); B() = adc(B(), AM_immediate_byte()); break; // ADC (ADCB, immediate)
case 0xE9: addCycles(4); B() = adc(B(), AM_indexed()); break; // ADC (ADCB, indexed) case 0xD9: addCycles(4); B() = adc(B(), AM_direct_byte()); break; // ADC (ADCB, direct)
case 0xF9: addCycles(4); B() = adc(B(), AM_extended()); break; // ADC (ADCB, extended) case 0xE9: addCycles(4); B() = adc(B(), AM_indexed_byte()); break; // ADC (ADCB, indexed)
case 0xF9: addCycles(4); B() = adc(B(), AM_extended_byte()); break; // ADC (ADCB, extended)
// ADD
case 0x8b: addCycles(2); A() = add(A(), AM_immediate_byte()); break; // ADD (ADDA, immediate)
case 0x9b: addCycles(4); A() = add(A(), AM_direct_byte()); break; // ADD (ADDA, direct)
case 0xab: addCycles(4); A() = add(A(), AM_indexed_byte()); break; // ADD (ADDA, indexed)
case 0xbb: addCycles(5); A() = add(A(), AM_extended_byte()); break; // ADD (ADDA, extended)
case 0xcb: addCycles(2); B() = add(B(), AM_immediate_byte()); break; // ADD (ADDB, immediate)
case 0xdb: addCycles(4); B() = add(B(), AM_direct_byte()); break; // ADD (ADDB, direct)
case 0xeb: addCycles(4); B() = add(B(), AM_indexed_byte()); break; // ADD (ADDB, indexed)
case 0xfb: addCycles(5); B() = add(B(), AM_extended_byte()); break; // ADD (ADDB, extended)
case 0xc3: addCycles(4); D() = add(D(), AM_immediate_word()); break; // ADD (ADDD, immediate)
case 0xd3: addCycles(6); D() = add(D(), AM_direct_word()); break; // ADD (ADDD, direct)
case 0xe3: addCycles(6); D() = add(D(), AM_indexed_word()); break; // ADD (ADDD, indexed)
case 0xf3: addCycles(7); D() = add(D(), AM_extended_word()); break; // ADD (ADDD, extended)
// NEG // NEG
case 0x00: addCycles(6); BUS().write(neg(AM_direct())); break; // NEG (direct) case 0x00: addCycles(6); BUS().write(neg(AM_direct_byte())); break; // NEG (direct)
case 0x40: addCycles(2); A() = neg(A()); break; // NEG (NEGA, inherent) case 0x40: addCycles(2); A() = neg(A()); break; // NEG (NEGA, inherent)
case 0x50: addCycles(2); B() = neg(B()); break; // NEG (NEGB, inherent) case 0x50: addCycles(2); B() = neg(B()); break; // NEG (NEGB, inherent)
case 0x60: addCycles(6); BUS().write(neg(AM_indexed())); break; // NEG (indexed) case 0x60: addCycles(6); BUS().write(neg(AM_indexed_byte())); break; // NEG (indexed)
case 0x70: addCycles(7); BUS().write(neg(AM_extended())); break; // NEG (extended) case 0x70: addCycles(7); BUS().write(neg(AM_extended_byte())); break; // NEG (extended)
default: default:
UNREACHABLE; UNREACHABLE;
@ -159,27 +176,48 @@ void EightBit::mc6809::Address_extended() {
// //
uint8_t EightBit::mc6809::AM_immediate() { uint8_t EightBit::mc6809::AM_immediate_byte() {
return fetchByte(); return fetchByte();
} }
uint8_t EightBit::mc6809::AM_direct() { uint8_t EightBit::mc6809::AM_direct_byte() {
Address_direct(); Address_direct();
return BUS().read(); return BUS().read();
} }
uint8_t EightBit::mc6809::AM_indexed() { uint8_t EightBit::mc6809::AM_indexed_byte() {
Address_indexed(); Address_indexed();
return BUS().read(); return BUS().read();
} }
uint8_t EightBit::mc6809::AM_extended() { uint8_t EightBit::mc6809::AM_extended_byte() {
Address_extended(); Address_extended();
return BUS().read(); return BUS().read();
} }
// //
EightBit::register16_t EightBit::mc6809::AM_immediate_word() {
return fetchWord();
}
EightBit::register16_t EightBit::mc6809::AM_direct_word() {
Address_direct();
return getWord();
}
EightBit::register16_t EightBit::mc6809::AM_indexed_word() {
Address_indexed();
return getWord();
}
EightBit::register16_t EightBit::mc6809::AM_extended_word() {
Address_extended();
return getWord();
}
//
void EightBit::mc6809::abx() { void EightBit::mc6809::abx() {
X() += B(); X() += B();
} }
@ -204,4 +242,13 @@ uint8_t EightBit::mc6809::add(uint8_t operand, uint8_t data, int carry) {
setFlag(CC(), ZF, result.low == 0); setFlag(CC(), ZF, result.low == 0);
setFlag(CC(), CF, result.word & Bit8); setFlag(CC(), CF, result.word & Bit8);
return result.low; return result.low;
} }
EightBit::register16_t EightBit::mc6809::add(register16_t operand, register16_t data) {
const uint32_t addition = operand.word + data.word;
const register16_t result = addition;
setFlag(CC(), NF, result.high & Bit7);
setFlag(CC(), ZF, result.word == 0);
setFlag(CC(), CF, addition & Bit16);
return result;
}