EightBit/MC6809/test/Board.cpp
Adrian Conlon fdbb28828f Apply the concept of powered components to the "board"
Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
2018-11-11 16:48:44 +00:00

135 lines
4.0 KiB
C++

#include "stdafx.h"
#include "Board.h"
Board::Board(const Configuration& configuration)
: m_configuration(configuration),
m_cpu(EightBit::mc6809(*this)),
m_disassembler(*this, m_cpu) {
}
void Board::powerOn() {
EightBit::Bus::powerOn();
// Get the CPU ready for action
CPU().powerOn();
CPU().raise(CPU().NMI());
CPU().raise(CPU().FIRQ());
CPU().reset();
// Get the ACIA ready for action
ADDRESS() = 0b1010000000000000;
ACIA().DATA() = EightBit::mc6850::CR0 | EightBit::mc6850::CR1; // Master reset
updateAciaPins(EightBit::Chip::PinLevel::Low);
ACIA().lower(ACIA().CTS());
ACIA().powerOn();
accessAcia();
}
void Board::powerOff() {
ACIA().powerOff();
CPU().powerOff();
EightBit::Bus::powerOff();
}
void Board::initialise() {
// Load our BASIC interpreter
const auto directory = m_configuration.getRomDirectory() + "\\";
loadHexFile(directory + "ExBasROM.hex");
// Once the reset has completed, we can wire the ACIA event handlers...
ACIA().Transmitting.connect(std::bind(&Board::Acia_Transmitting, this, std::placeholders::_1));
// Wire bus events...
WrittenByte.connect(std::bind(&Board::Bus_WrittenByte_Acia, this, std::placeholders::_1));
ReadingByte.connect(std::bind(&Board::Bus_ReadingByte_Acia, this, std::placeholders::_1));
// Wire CPU events
CPU().ExecutedInstruction.connect(std::bind(&Board::Cpu_ExecutedInstruction_Acia, this, std::placeholders::_1));
if (m_configuration.isDebugMode()) {
CPU().ExecutingInstruction.connect(std::bind(&Board::Cpu_ExecutingInstruction_Debug, this, std::placeholders::_1));
CPU().ExecutedInstruction.connect(std::bind(&Board::Cpu_ExecutedInstruction_Debug, this, std::placeholders::_1));
}
if (m_configuration.terminatesEarly())
CPU().ExecutedInstruction.connect(std::bind(&Board::Cpu_ExecutedInstruction_Terminator, this, std::placeholders::_1));
}
void Board::Cpu_ExecutingInstruction_Debug(EightBit::mc6809&) {
m_disassembleAt = CPU().PC();
m_ignoreDisassembly = m_disassembler.ignore();
}
void Board::Cpu_ExecutedInstruction_Debug(EightBit::mc6809&) {
if (!m_ignoreDisassembly)
std::cout << m_disassembler.trace(m_disassembleAt) << " " << ACIA().dumpStatus() << std::endl;
}
EightBit::MemoryMapping Board::mapping(uint16_t address) {
if (address < 0x8000)
return { m_ram, 0x0000, 0xffff, EightBit::MemoryMapping::ReadWrite };
if (address < 0xa000)
return { m_unused2000, 0x8000, 0xffff, EightBit::MemoryMapping::ReadOnly };
if (address < 0xc000)
return { m_io, 0xa000, 0xffff, EightBit::MemoryMapping::ReadWrite };
return { m_rom, 0xc000, 0xffff, EightBit::MemoryMapping::ReadOnly };
}
void Board::Bus_WrittenByte_Acia(EightBit::EventArgs&) {
updateAciaPins(EightBit::Chip::Low);
if (ACIA().selected()) {
ACIA().DATA() = peek(ADDRESS());
accessAcia();
}
}
void Board::Bus_ReadingByte_Acia(EightBit::EventArgs&) {
updateAciaPins(EightBit::Chip::High);
if (accessAcia())
poke(ADDRESS(), ACIA().DATA());
}
void Board::updateAciaPins(const EightBit::Chip::PinLevel rw) {
ACIA().RW() = rw;
ACIA().DATA() = DATA();
ACIA().match(ACIA().RS(), ADDRESS().word & EightBit::Chip::Bit0);
ACIA().match(ACIA().CS0(), ADDRESS().word & EightBit::Chip::Bit15);
ACIA().match(ACIA().CS1(), ADDRESS().word & EightBit::Chip::Bit13);
ACIA().match(ACIA().CS2(), ADDRESS().word & EightBit::Chip::Bit14);
}
void Board::Cpu_ExecutedInstruction_Terminator(EightBit::mc6809&) {
assert(CPU().cycles() > 0);
m_totalCycleCount += CPU().cycles();
if (m_totalCycleCount > Configuration::TerminationCycles)
powerOff();
}
void Board::Cpu_ExecutedInstruction_Acia(EightBit::mc6809&) {
assert(CPU().cycles() > 0);
m_frameCycleCount -= CPU().cycles();
if (m_frameCycleCount < 0) {
if (_kbhit()) {
ACIA().RDR() = _getch();
ACIA().markReceiveStarting();
}
m_frameCycleCount = Configuration::FrameCycleInterval;
}
}
void Board::Acia_Transmitting(EightBit::EventArgs&) {
std::cout << ACIA().TDR();
ACIA().markTransmitComplete();
}
bool Board::accessAcia() {
ACIA().raise(ACIA().E());
const bool accessed = ACIA().tick();
ACIA().lower(ACIA().E());
return accessed;
}