mirror of
https://github.com/MoleskiCoder/EightBit.git
synced 2024-09-01 15:29:11 +00:00
202 lines
4.9 KiB
C++
202 lines
4.9 KiB
C++
#pragma once
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#include <cstdint>
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#include <Ram.h>
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#include <Processor.h>
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#include <Register.h>
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#include <Signal.h>
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namespace EightBit {
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namespace GameBoy {
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class Bus;
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class IoRegisters final : public EightBit::Ram {
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public:
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enum {
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BASE = 0xFF00,
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// Port/Mode Registers
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P1 = 0x0, // R/W Mask5
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SB = 0x1, // R/W Mask8
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SC = 0x2, // R/W Bit7 | Bit0
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// Timer control
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DIV = 0x4, // R/W Mask8
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TIMA = 0x5, // R/W Mask8
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TMA = 0x6, // R/W Mask8
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TAC = 0x7, // R/W Mask3
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// Interrupt Flags
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IF = 0xF, // R/W Mask5
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IE = 0xFF, // R/W Mask5
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// Sound Registers
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NR10 = 0x10, // R/W Mask7
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NR11 = 0x11, // R/W Bit7 | Bit6
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NR12 = 0x12, // R/W Mask8
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NR13 = 0x13, // W 0
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NR14 = 0x14, // R/W Bit6
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NR21 = 0x16, // R/W Bit7 | Bit6
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NR22 = 0x17, // R/W Mask8
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NR23 = 0x18, // W 0
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NR24 = 0x19, // R/W Bit6
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NR30 = 0x1A, // R/W Bit7
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NR31 = 0x1B, // R/W Mask8
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NR32 = 0x1C, // R/W Bit6 | Bit5
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NR33 = 0x1D, // W 0
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NR34 = 0x1E, // R/W Bit6
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NR41 = 0x20, // R/W Mask6
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NR42 = 0x21, // R/W Mask8
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NR43 = 0x22, // R/W Mask8
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NR44 = 0x23, // R/W Bit6
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NR50 = 0x24, // R/W Mask8
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NR51 = 0x25, // R/W Mask8
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NR52 = 0x26, // R/W Mask8 Mask8
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WAVE_PATTERN_RAM_START = 0x30,
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WAVE_PATTERN_RAM_END = 0x3F,
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// LCD Display Registers
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LCDC = 0x40, // R/W Mask8
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STAT = 0x41, // R/W Mask7
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SCY = 0x42, // R/W Mask8
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SCX = 0x43, // R/W Mask8
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LY = 0x44, // R Mask8 zeroed
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LYC = 0x45, // R/W Mask8
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DMA = 0x46, // W 0
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BGP = 0x47, // R/W Mask8
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OBP0 = 0x48, // R/W Mask8
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OBP1 = 0x49, // R/W Mask8
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WY = 0x4A, // R/W Mask8
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WX = 0x4B, // R/W Mask8
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// Boot rom control
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BOOT_DISABLE = 0x50,
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};
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// IF and IE flags
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enum Interrupts {
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VerticalBlank = Chip::Bit0, // VBLANK
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DisplayControlStatus = Chip::Bit1, // LCDC Status
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TimerOverflow = Chip::Bit2, // Timer Overflow
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SerialTransfer = Chip::Bit3, // Serial Transfer
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KeypadPressed = Chip::Bit4 // Hi-Lo transition of P10-P13
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};
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enum LcdcControl {
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DisplayBackground = Chip::Bit0,
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ObjectEnable = Chip::Bit1,
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ObjectBlockCompositionSelection = Chip::Bit2,
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BackgroundCodeAreaSelection = Chip::Bit3,
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BackgroundCharacterDataSelection = Chip::Bit4,
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WindowEnable = Chip::Bit5,
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WindowCodeAreaSelection = Chip::Bit6,
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LcdEnable = Chip::Bit7
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};
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enum LcdStatusMode {
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HBlank = 0b00,
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VBlank = 0b01,
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SearchingOamRam = 0b10,
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TransferringDataToLcd = 0b11
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};
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IoRegisters(Bus& bus);
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Signal<int> DisplayStatusModeUpdated;
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void reset();
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void transferDma();
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void triggerInterrupt(const int cause) {
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poke(IF, peek(IF) | cause);
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}
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void checkTimers(int cycles);
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int timerClockTicks();
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int timerClock();
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bool timerEnabled();
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bool timerDisabled();
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void incrementDIV(int cycles);
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void incrementTIMA();
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void incrementLY();
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void resetLY();
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void updateLcdStatusMode(int mode);
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void disableBootRom() { m_disableBootRom = true; }
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void enableBootRom() { m_disableBootRom = false; }
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auto bootRomDisabled() const { return m_disableBootRom; }
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auto bootRomEnabled() const { return !bootRomDisabled(); }
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void pressRight() { m_p14 = m_p10 = false; triggerKeypadInterrupt(); }
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void releaseRight() { m_p14 = m_p10 = true; }
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void pressLeft() { m_p14 = m_p11 = false, triggerKeypadInterrupt(); }
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void releaseLeft() { m_p14 = m_p11 = true; }
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void pressUp() { m_p14 = m_p12 = false, triggerKeypadInterrupt(); }
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void releaseUp() { m_p14 = m_p12 = true; }
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void pressDown() { m_p14 = m_p13 = false, triggerKeypadInterrupt(); }
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void releaseDown() { m_p14 = m_p13 = true; }
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void pressA() { m_p15 = m_p10 = false, triggerKeypadInterrupt(); }
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void releaseA() { m_p15 = m_p10 = true; }
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void pressB() { m_p15 = m_p11 = false, triggerKeypadInterrupt(); }
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void releaseB() { m_p15 = m_p11 = true; }
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void pressSelect() { m_p15 = m_p12 = false, triggerKeypadInterrupt(); }
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void releaseSelect() { m_p15 = m_p12 = true; }
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void pressStart() { m_p15 = m_p13 = false, triggerKeypadInterrupt(); }
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void releaseStart() { m_p15 = m_p13 = true; }
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private:
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Bus& m_bus;
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bool m_disableBootRom = false;
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register16_t m_divCounter = { 0xab, 0xcc };
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int m_timerCounter = 0;
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int m_timerRate = 0;
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register16_t m_dmaAddress;
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bool m_dmaTransferActive = false;
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bool m_scanP15 = false;
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bool m_scanP14 = false;
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bool m_p15 = true; // misc keys
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bool m_p14 = true; // direction keys
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bool m_p13 = true; // down/start
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bool m_p12 = true; // up/select
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bool m_p11 = true; // left/b
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bool m_p10 = true; // right/a
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void checkTimer(int cycles);
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void mask(const uint16_t address, const uint8_t masking) {
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poke(address, peek(address) | ~masking);
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}
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void triggerKeypadInterrupt() {
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triggerInterrupt(Interrupts::KeypadPressed);
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}
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void Bus_WrittenByte(EightBit::EventArgs);
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void Bus_ReadingByte(EightBit::EventArgs);
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};
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}
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} |