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Const some more bus/processor usage, and ensure the data bus is a member, not a reference to memory.

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Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
This commit is contained in:
Adrian Conlon
2018-06-10 00:40:56 +01:00
parent 7531f8a24a
commit 3e854c7c49
28 changed files with 358 additions and 151 deletions
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src/Bus.cpp
+17 -27
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@@ -3,26 +3,7 @@
#include "EightBitCompilerDefinitions.h"
EightBit::register16_t& EightBit::Bus::ADDRESS() {
return m_address;
}
uint8_t& EightBit::Bus::DATA() {
return *m_data;
}
uint8_t& EightBit::Bus::placeDATA(const uint8_t value) {
m_temporary = value;
m_data = &m_temporary;
return DATA();
}
uint8_t& EightBit::Bus::referenceDATA(uint8_t& value) {
m_data = &value;
return DATA();
}
uint8_t EightBit::Bus::peek(const uint16_t address) {
uint8_t EightBit::Bus::peek(const uint16_t address) const {
bool rom;
return reference(address, rom);
}
@@ -32,7 +13,7 @@ void EightBit::Bus::poke(const uint16_t address, const uint8_t value) {
reference(address, rom) = value;
}
uint16_t EightBit::Bus::peekWord(const uint16_t address) {
uint16_t EightBit::Bus::peekWord(const uint16_t address) const {
register16_t returned;
returned.low = peek(address);
returned.high = peek(address + 1);
@@ -41,9 +22,9 @@ uint16_t EightBit::Bus::peekWord(const uint16_t address) {
uint8_t EightBit::Bus::read() {
ReadingByte.fire(ADDRESS().word);
const auto returned = reference();
DATA() = reference();
ReadByte.fire(ADDRESS().word);
return returned;
return DATA();
}
uint8_t EightBit::Bus::read(const uint16_t offset) {
@@ -56,12 +37,17 @@ uint8_t EightBit::Bus::read(const register16_t address) {
return read();
}
void EightBit::Bus::write(const uint8_t value) {
void EightBit::Bus::write() {
WritingByte.fire(ADDRESS().word);
reference() = value;
reference() = DATA();
WrittenByte.fire(ADDRESS().word);
}
void EightBit::Bus::write(const uint8_t value) {
DATA() = value;
write();
}
void EightBit::Bus::write(const uint16_t offset, const uint8_t value) {
ADDRESS().word = offset;
write(value);
@@ -72,8 +58,12 @@ void EightBit::Bus::write(const register16_t address, const uint8_t value) {
write(value);
}
uint8_t EightBit::Bus::reference() const {
bool rom;
return reference(ADDRESS().word, rom);
}
uint8_t& EightBit::Bus::reference() {
bool rom;
auto& value = reference(ADDRESS().word, rom);
return rom ? placeDATA(value) : referenceDATA(value);
return reference(ADDRESS().word, rom);
}