6502/EightBit
1
0
Fork 0
mirror of https://github.com/MoleskiCoder/EightBit.git synced 2025-01-18 01:29:49 +00:00
Code Issues Projects Releases Wiki Activity

Start refactoring the processor classes to allow big/little endian processors to be specified.

Browse Source 
Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
This commit is contained in:
Adrian Conlon 2018-08-17 21:53:49 +01:00
parent 677b9a608e
commit cc64e114a9
9 changed files with 151 additions and 50 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
M6502/inc/mos6502.h
View File

@ -7,11 +7,11 @@
#include <cassert>
#include <Bus.h>
#include <Processor.h>
#include <LittleEndianProcessor.h>
#include <Signal.h>
namespace EightBit {
class MOS6502 : public Processor {
class MOS6502 : public LittleEndianProcessor {
public:
enum StatusBits {
NF = Bit7, // Negative
@ -65,10 +65,6 @@ namespace EightBit {
adjustNegative(datum);
}
register16_t getWordPaged(uint8_t page, uint8_t offset);
uint8_t getBytePaged(uint8_t page, uint8_t offset);
void setBytePaged(uint8_t page, uint8_t offset, uint8_t value);
virtual void push(uint8_t value) final;
virtual uint8_t pop() final;

17
M6502/src/mos6502.cpp
View File

@ -2,7 +2,7 @@
#include "mos6502.h"
EightBit::MOS6502::MOS6502(Bus& bus)
: Processor(bus) {}
: LittleEndianProcessor(bus) {}
void EightBit::MOS6502::powerOn() {
@ -50,21 +50,6 @@ void EightBit::MOS6502::reset() {
jump(getWordPaged(0xff, RSTvector));
}
EightBit::register16_t EightBit::MOS6502::getWordPaged(uint8_t page, uint8_t offset) {
const auto low = getBytePaged(page, offset);
++BUS().ADDRESS().low;
const auto high = BUS().read();
return register16_t(low, high);
}
uint8_t EightBit::MOS6502::getBytePaged(uint8_t page, uint8_t offset) {
return BUS().read(register16_t(offset, page));
}
void EightBit::MOS6502::setBytePaged(uint8_t page, uint8_t offset, uint8_t value) {
BUS().write(register16_t(offset, page), value);
}
void EightBit::MOS6502::interrupt(uint8_t vector) {
raise(HALT());
pushWord(PC());

56
inc/BigEndianProcessor.h Normal file
View File

@ -0,0 +1,56 @@
#pragma once
#include "Bus.h"
#include "Register.h"
#include "Processor.h"
namespace EightBit {
class BigEndianProcessor : public Processor {
protected:
BigEndianProcessor(Bus& memory) : Processor(memory) {}
virtual ~BigEndianProcessor() = default;
virtual register16_t getWord() {
const auto high = BUS().read();
++BUS().ADDRESS();
const auto low = BUS().read();
return register16_t(low, high);
}
virtual void setWord(const register16_t value) {
BUS().write(value.high);
++BUS().ADDRESS();
BUS().write(value.low);
}
virtual register16_t getWordPaged(uint8_t page, uint8_t offset) override {
const auto high = getBytePaged(page, offset);
++BUS().ADDRESS().low;
const auto low = BUS().read();
return register16_t(low, high);
}
virtual void setWordPaged(uint8_t page, uint8_t offset, register16_t value) override {
setBytePaged(page, offset, value.high);
++BUS().ADDRESS().low;
BUS().read(value.low);
}
virtual register16_t fetchWord() final {
const auto high = fetchByte();
const auto low = fetchByte();
return register16_t(low, high);
}
virtual void pushWord(const register16_t value) final {
push(value.low);
push(value.high);
}
virtual register16_t popWord() final {
const auto high = pop();
const auto low = pop();
return register16_t(low, high);
}
};
}

8
inc/IntelProcessor.h
View File

@ -4,13 +4,13 @@
#include <array>
#include "Bus.h"
#include "Processor.h"
#include "LittleEndianProcessor.h"
#include "Register.h"
#include "EightBitCompilerDefinitions.h"
namespace EightBit {
class IntelProcessor : public Processor
class IntelProcessor : public LittleEndianProcessor
{
public:
struct opcode_decoded_t {
@ -122,8 +122,8 @@ namespace EightBit {
//
register16_t getWord();
void setWord(register16_t value);
virtual register16_t getWord() final;
virtual void setWord(register16_t value) final;
//

56
inc/LittleEndianProcessor.h Normal file
View File

@ -0,0 +1,56 @@
#pragma once
#include "Bus.h"
#include "Register.h"
#include "Processor.h"
namespace EightBit {
class LittleEndianProcessor : public Processor {
protected:
LittleEndianProcessor(Bus& memory) : Processor(memory) {}
virtual ~LittleEndianProcessor() = default;
virtual register16_t getWord() {
const auto low = BUS().read();
++BUS().ADDRESS();
const auto high = BUS().read();
return register16_t(low, high);
}
virtual void setWord(const register16_t value) {
BUS().write(value.low);
++BUS().ADDRESS();
BUS().write(value.high);
}
virtual register16_t getWordPaged(uint8_t page, uint8_t offset) override {
const auto low = getBytePaged(page, offset);
++BUS().ADDRESS().low;
const auto high = BUS().read();
return register16_t(low, high);
}
virtual void setWordPaged(uint8_t page, uint8_t offset, register16_t value) override {
setBytePaged(page, offset, value.low);
++BUS().ADDRESS().low;
BUS().read(value.high);
}
virtual register16_t fetchWord() final {
const auto low = fetchByte();
const auto high = fetchByte();
return register16_t(low, high);
}
virtual void pushWord(const register16_t value) final {
push(value.high);
push(value.low);
}
virtual register16_t popWord() final {
const auto low = pop();
const auto high = pop();
return register16_t(low, high);
}
};
}

34
inc/Processor.h
View File

@ -97,7 +97,7 @@ namespace EightBit {
static void clearFlag(uint8_t& f, const int flag, const int condition) { clearFlag(f, flag, !!condition); }
static void clearFlag(uint8_t& f, const int flag, const uint32_t condition) { clearFlag(f, flag, !!condition); }
static void clearFlag(uint8_t& f, const int flag, const bool condition) { condition ? clearFlag(f, flag) : setFlag(f, flag); }
static void clearFlag(uint8_t& f, const int flag, const bool condition) { setFlag(f, flag, !condition); }
Processor(Bus& memory);
virtual ~Processor() = default;
@ -108,29 +108,31 @@ namespace EightBit {
void halt() { --PC(); lower(HALT()); }
void proceed() { ++PC(); raise(HALT()); }
uint8_t getBytePaged(uint8_t page, uint8_t offset) {
return BUS().read(register16_t(offset, page));
}
void setBytePaged(uint8_t page, uint8_t offset, uint8_t value) {
BUS().write(register16_t(offset, page), value);
}
uint8_t fetchByte() {
return BUS().read(PC()++);
}
register16_t fetchWord() {
const auto low = fetchByte();
const auto high = fetchByte();
return register16_t(low, high);
}
virtual register16_t getWord() = 0;
virtual void setWord(register16_t value) = 0;
virtual register16_t getWordPaged(uint8_t page, uint8_t offset) = 0;
virtual void setWordPaged(uint8_t page, uint8_t offset, register16_t value) = 0;
virtual register16_t fetchWord() = 0;
virtual void push(uint8_t value) = 0;
virtual uint8_t pop() = 0;
void pushWord(const register16_t value) {
push(value.high);
push(value.low);
}
register16_t popWord() {
const auto low = pop();
const auto high = pop();
return register16_t(low, high);
}
virtual void pushWord(const register16_t value) = 0;
virtual register16_t popWord() = 0;
void jump(const register16_t destination) {
PC() = destination;

2
src/EightBit.vcxproj
View File

@ -136,11 +136,13 @@
</Link>
</ItemDefinitionGroup>
<ItemGroup>
<ClInclude Include="..\inc\BigEndianProcessor.h" />
<ClInclude Include="..\inc\Bus.h" />
<ClInclude Include="..\inc\EightBitCompilerDefinitions.h" />
<ClInclude Include="..\inc\EventArgs.h" />
<ClInclude Include="..\inc\InputOutput.h" />
<ClInclude Include="..\inc\IntelProcessor.h" />
<ClInclude Include="..\inc\LittleEndianProcessor.h" />
<ClInclude Include="..\inc\Memory.h" />
<ClInclude Include="..\inc\Processor.h" />
<ClInclude Include="..\inc\Ram.h" />

6
src/EightBit.vcxproj.filters
View File

@ -47,6 +47,12 @@
<ClInclude Include="..\inc\EightBitCompilerDefinitions.h">
<Filter>Header Files</Filter>
</ClInclude>
<ClInclude Include="..\inc\LittleEndianProcessor.h">
<Filter>Header Files</Filter>
</ClInclude>
<ClInclude Include="..\inc\BigEndianProcessor.h">
<Filter>Header Files</Filter>
</ClInclude>
</ItemGroup>
<ItemGroup>
<ClCompile Include="stdafx.cpp">

14
src/IntelProcessor.cpp
View File

@ -2,7 +2,7 @@
#include "IntelProcessor.h"
EightBit::IntelProcessor::IntelProcessor(Bus& bus)
: Processor(bus) {
: LittleEndianProcessor(bus) {
for (int i = 0; i < 0x100; ++i)
m_decodedOpcodes[i] = i;
}
@ -21,14 +21,12 @@ uint8_t EightBit::IntelProcessor::pop() {
}
EightBit::register16_t EightBit::IntelProcessor::getWord() {
const auto low = BUS().read();
MEMPTR() = ++BUS().ADDRESS();
const auto high = BUS().read();
return register16_t(low, high);
const auto returned = LittleEndianProcessor::getWord();
MEMPTR() = BUS().ADDRESS();
return returned;
}
void EightBit::IntelProcessor::setWord(const register16_t value) {
BUS().write(value.low);
MEMPTR() = ++BUS().ADDRESS();
BUS().write(value.high);
LittleEndianProcessor::setWord(value);
MEMPTR() = BUS().ADDRESS();
}