GameBoyAdvanceSerial.as

package  {
	
	public class GameBoyAdvanceSerial {
		
		public var IOCore;
		public var SIODATA_A = 0xFFFF;
		public var SIODATA_B = 0xFFFF;
		public var SIODATA_C = 0xFFFF;
		public var SIODATA_D = 0xFFFF;
		public var SIOShiftClockExternal = true;
		public var SIOShiftClockDivider = 0x40;
		public var SIOCNT0_DATA = 0x0C;
		public var SIOTransferStarted = false;
		public var SIOMULT_PLAYER_NUMBER = 0;
		public var SIOCOMMERROR = false;
		public var SIOBaudRate = 0;
		public var SIOCNT_UART_CTS = false;
		public var SIOCNT_UART_MISC = 0;
		public var SIOCNT_UART_FIFO = 0;
		public var SIOCNT_IRQ = false;
		public var SIOCNT_MODE = 0;
		public var SIOCNT_UART_RECV_ENABLE = false;
		public var SIOCNT_UART_SEND_ENABLE = false;
		public var SIOCNT_UART_PARITY_ENABLE = false;
		public var SIOCNT_UART_FIFO_ENABLE = false;
		public var SIODATA8 = 0xFFFF;
		public var RCNTMode = 0;
		public var RCNTIRQ = false;
		public var RCNTDataBits = 0;
		public var RCNTDataBitFlow = 0;
		public var JOYBUS_IRQ = false;
		public var JOYBUS_CNTL_FLAGS = 0;
		public var JOYBUS_RECV0 = 0xFF;
		public var JOYBUS_RECV1 = 0xFF;
		public var JOYBUS_RECV2 = 0xFF;
		public var JOYBUS_RECV3 = 0xFF;
		public var JOYBUS_SEND0 = 0xFF;
		public var JOYBUS_SEND1 = 0xFF;
		public var JOYBUS_SEND2 = 0xFF;
		public var JOYBUS_SEND3 = 0xFF;
		public var JOYBUS_STAT = 0;
		public var shiftClocks = 0;
		public var serialBitsShifted = 0;
		
		
		public function GameBoyAdvanceSerial(IOCore) {
			// constructor code
			this.IOCore = IOCore;
			this.initialize();
		}
		
		public function initialize() {
			this.SIODATA_A = 0xFFFF;
			this.SIODATA_B = 0xFFFF;
			this.SIODATA_C = 0xFFFF;
			this.SIODATA_D = 0xFFFF;
			this.SIOShiftClockExternal = true;
			this.SIOShiftClockDivider = 0x40;
			this.SIOCNT0_DATA = 0x0C;
			this.SIOTransferStarted = false;
			this.SIOMULT_PLAYER_NUMBER = 0;
			this.SIOCOMMERROR = false;
			this.SIOBaudRate = 0;
			this.SIOCNT_UART_CTS = false;
			this.SIOCNT_UART_MISC = 0;
			this.SIOCNT_UART_FIFO = 0;
			this.SIOCNT_IRQ = false;
			this.SIOCNT_MODE = 0;
			this.SIOCNT_UART_RECV_ENABLE = false;
			this.SIOCNT_UART_SEND_ENABLE = false;
			this.SIOCNT_UART_PARITY_ENABLE = false;
			this.SIOCNT_UART_FIFO_ENABLE = false;
			this.SIODATA8 = 0xFFFF;
			this.RCNTMode = 0;
			this.RCNTIRQ = false;
			this.RCNTDataBits = 0;
			this.RCNTDataBitFlow = 0;
			this.JOYBUS_IRQ = false;
			this.JOYBUS_CNTL_FLAGS = 0;
			this.JOYBUS_RECV0 = 0xFF;
			this.JOYBUS_RECV1 = 0xFF;
			this.JOYBUS_RECV2 = 0xFF;
			this.JOYBUS_RECV3 = 0xFF;
			this.JOYBUS_SEND0 = 0xFF;
			this.JOYBUS_SEND1 = 0xFF;
			this.JOYBUS_SEND2 = 0xFF;
			this.JOYBUS_SEND3 = 0xFF;
			this.JOYBUS_STAT = 0;
			this.shiftClocks = 0;
			this.serialBitsShifted = 0;
		}
		public var SIOMultiplayerBaudRate = [
			  9600,
			 38400,
			 57600,
			115200
		];
		public function addClocks(clocks) {
			if (this.RCNTMode < 2) {
				switch (this.SIOCNT_MODE) {
					case 0:
					case 1:
						if (this.SIOTransferStarted && !this.SIOShiftClockExternal) {
							this.shiftClocks += clocks;
							while (this.shiftClocks >= this.SIOShiftClockDivider) {
								this.shiftClocks -= this.SIOShiftClockDivider;
								this.clockSerial();
							}
						}
						break;
					case 2:
						if (this.SIOTransferStarted && this.SIOMULT_PLAYER_NUMBER == 0) {
							this.shiftClocks += clocks;
							while (this.shiftClocks >= this.SIOShiftClockDivider) {
								this.shiftClocks -= this.SIOShiftClockDivider;
								this.clockMultiplayer();
							}
						}
						break;
					case 3:
						if (this.SIOCNT_UART_SEND_ENABLE && !this.SIOCNT_UART_CTS) {
							this.shiftClocks += clocks;
							while (this.shiftClocks >= this.SIOShiftClockDivider) {
								this.shiftClocks -= this.SIOShiftClockDivider;
								this.clockUART();
							}
						}
				}
			}
		}
		public function clockSerial() {
			//Emulate as if no slaves connected:
			++this.serialBitsShifted;
			if (this.SIOCNT_MODE == 0) {
				//8-bit
				this.SIODATA8 = ((this.SIODATA8 << 1) | 1) & 0xFFFF;
				if (this.serialBitsShifted == 8) {
					this.SIOTransferStarted = false;
					this.serialBitsShifted = 0;
					if (this.SIOCNT_IRQ) {
						this.IOCore.irq.requestIRQ(0x80);
					}
				}
			}
			else {
				//32-bit
				this.SIODATA_D = ((this.SIODATA_D << 1) & 0xFE) | (this.SIODATA_C >> 7);
				this.SIODATA_C = ((this.SIODATA_C << 1) & 0xFE) | (this.SIODATA_B >> 7);
				this.SIODATA_B = ((this.SIODATA_B << 1) & 0xFE) | (this.SIODATA_A >> 7);
				this.SIODATA_A = ((this.SIODATA_A << 1) & 0xFE) | 1;
				if (this.serialBitsShifted == 32) {
					this.SIOTransferStarted = false;
					this.serialBitsShifted = 0;
					if (this.SIOCNT_IRQ) {
						this.IOCore.irq.requestIRQ(0x80);
					}
				}
			}
		}
		public function clockMultiplayer() {
			//Emulate as if no slaves connected:
			this.SIODATA_A = this.SIODATA8;
			this.SIODATA_B = 0xFFFF;
			this.SIODATA_C = 0xFFFF;
			this.SIODATA_D = 0xFFFF;
			this.SIOTransferStarted = false;
			this.SIOCOMMERROR = true;
			if (this.SIOCNT_IRQ) {
				this.IOCore.irq.requestIRQ(0x80);
			}
		}
		public function clockUART() {
			++this.serialBitsShifted;
			if (this.SIOCNT_UART_FIFO_ENABLE) {
				if (this.serialBitsShifted == 8) {
					this.serialBitsShifted = 0;
					this.SIOCNT_UART_FIFO = Math.max(this.SIOCNT_UART_FIFO - 1, 0);
					if (this.SIOCNT_UART_FIFO == 0 && this.SIOCNT_IRQ) {
						this.IOCore.irq.requestIRQ(0x80);
					}
				}
			}
			else {
				if (this.serialBitsShifted == 8) {
					this.serialBitsShifted = 0;
					if (this.SIOCNT_IRQ) {
						this.IOCore.irq.requestIRQ(0x80);
					}
				}
			}
		}
		public function writeSIODATA_A0(data) {
			this.SIODATA_A &= 0xFF00;
			this.SIODATA_A |= data;
		}
		public function readSIODATA_A0() {
			return this.SIODATA_A & 0xFF;
		}
		public function writeSIODATA_A1(data) {
			this.SIODATA_A &= 0xFF;
			this.SIODATA_A |= data << 8;
		}
		public function readSIODATA_A1() {
			return this.SIODATA_A >> 8;
		}
		public function writeSIODATA_B0(data) {
			this.SIODATA_B &= 0xFF00;
			this.SIODATA_B |= data;
		}
		public function readSIODATA_B0() {
			return this.SIODATA_B & 0xFF;
		}
		public function writeSIODATA_B1(data) {
			this.SIODATA_B &= 0xFF;
			this.SIODATA_B |= data << 8;
		}
		public function readSIODATA_B1() {
			return this.SIODATA_B >> 8;
		}
		public function writeSIODATA_C0(data) {
			this.SIODATA_C &= 0xFF00;
			this.SIODATA_C |= data;
		}
		public function readSIODATA_C0() {
			return this.SIODATA_C & 0xFF;
		}
		public function writeSIODATA_C1(data) {
			this.SIODATA_C &= 0xFF;
			this.SIODATA_C |= data << 8;
		}
		public function readSIODATA_C1() {
			return this.SIODATA_C >> 8;
		}
		public function writeSIODATA_D0(data) {
			this.SIODATA_D &= 0xFF00;
			this.SIODATA_D |= data;
		}
		public function readSIODATA_D0() {
			return this.SIODATA_D & 0xFF;
		}
		public function writeSIODATA_D1(data) {
			this.SIODATA_D &= 0xFF;
			this.SIODATA_D |= data << 8;
		}
		public function readSIODATA_D1() {
			return this.SIODATA_D >> 8;
		}
		public function writeSIOCNT0(data) {
			if (this.RCNTMode < 0x2) {
				switch (this.SIOCNT_MODE) {
					//8-Bit:
					case 0:
					//32-Bit:
					case 1:
						this.SIOShiftClockExternal = ((data & 0x1) == 0x1);
						this.SIOShiftClockDivider = ((data & 0x2) == 0x2) ? 0x8 : 0x40;
						this.SIOCNT0_DATA = data & 0xB;
						if ((data & 0x80) == 0x80) {
							if (!this.SIOTransferStarted) {
								this.SIOTransferStarted = true;
								this.serialBitsShifted = 0;
								this.shiftClocks = 0;
							}
						}
						else {
							this.SIOTransferStarted = false;
						}
						break;
					//Multiplayer:
					case 2:
						this.SIOBaudRate = data & 0x3;
						this.SIOShiftClockDivider = this.SIOMultiplayerBaudRate[this.SIOBaudRate];
						this.SIOMULT_PLAYER_NUMBER = (data >> 4) & 0x3;
						this.SIOCOMMERROR = ((data & 0x40) == 0x40);
						if ((data & 0x80) == 0x80) {
							if (!this.SIOTransferStarted) {
								this.SIOTransferStarted = true;
								if (this.SIOMULT_PLAYER_NUMBER == 0) {
									this.SIODATA_A = 0xFFFF;
									this.SIODATA_B = 0xFFFF;
									this.SIODATA_C = 0xFFFF;
									this.SIODATA_D = 0xFFFF;
								}
								this.serialBitsShifted = 0;
								this.shiftClocks = 0;
							}
						}
						else {
							this.SIOTransferStarted = false;
						}
						break;
					//UART:
					case 3:
						this.SIOBaudRate = data & 0x3;
						this.SIOShiftClockDivider = this.SIOMultiplayerBaudRate[this.SIOBaudRate];
						this.SIOCNT_UART_MISC = (data & 0xCF) >> 2;
						this.SIOCNT_UART_CTS = ((data & 0x4) == 0x4);
				}
			}
		}
		public function readSIOCNT0() {
			if (this.RCNTMode < 0x2) {
				switch (this.SIOCNT_MODE) {
					//8-Bit:
					case 0:
					//32-Bit:
					case 1:
						return ((this.SIOTransferStarted) ? 0x80 : 0) | 0x74 | this.SIOCNT0_DATA;
					//Multiplayer:
					case 2:
						return ((this.SIOTransferStarted) ? 0x80 : 0) | ((this.SIOCOMMERROR) ? 0x40 : 0) | (this.SIOMULT_PLAYER_NUMBER << 4) | this.SIOBaudRate;
					//UART:
					case 3:
						return (this.SIOCNT_UART_MISC << 2) | ((this.SIOCNT_UART_FIFO == 4) ? 0x10 : 0) | 0x20 | this.SIOBaudRate;
				}
			}
			return 0xFF;
		}
		public function writeSIOCNT1(data) {
			this.SIOCNT_IRQ = ((data & 0x40) == 0x40);
			this.SIOCNT_MODE = (data >> 4) & 0x3;
			this.SIOCNT_UART_RECV_ENABLE = ((data & 0x8) == 0x8);
			this.SIOCNT_UART_SEND_ENABLE = ((data & 0x4) == 0x4);
			this.SIOCNT_UART_PARITY_ENABLE = ((data & 0x2) == 0x2);
			this.SIOCNT_UART_FIFO_ENABLE = ((data & 0x1) == 0x1);
		}
		public function readSIOCNT1() {
			return (0x80 | (this.SIOCNT_IRQ ? 0x40 : 0) | (this.SIOCNT_MODE << 4) | ((this.SIOCNT_UART_RECV_ENABLE) ? 0x8 : 0) |
			((this.SIOCNT_UART_SEND_ENABLE) ? 0x4 : 0) | ((this.SIOCNT_UART_PARITY_ENABLE) ? 0x2 : 0) | ((this.SIOCNT_UART_FIFO_ENABLE) ? 0x2 : 0));
		}
		public function writeSIODATA8_0(data) {
			this.SIODATA8 &= 0xFF00;
			this.SIODATA8 |= data;
			if (this.RCNTMode < 0x2 && this.SIOCNT_MODE == 3 && this.SIOCNT_UART_FIFO_ENABLE) {
				this.SIOCNT_UART_FIFO = Math.min(this.SIOCNT_UART_FIFO + 1, 4);
			}
		}
		public function readSIODATA8_0() {
			return this.SIODATA8 & 0xFF;
		}
		public function writeSIODATA8_1(data) {
			this.SIODATA8 &= 0xFF;
			this.SIODATA8 |= data << 8;
		}
		public function readSIODATA8_1() {
			return this.SIODATA8 >> 8;
		}
		public function writeRCNT0(data) {
			if (this.RCNTMode == 0x2) {
				//General Comm:
				var oldDataBits = this.RCNTDataBits;
				this.RCNTDataBits = data & 0xF;	//Device manually controls SI/SO/SC/SD here.
				this.RCNTDataBitFlow = data >> 4;
				if (this.RCNTIRQ && ((oldDataBits ^ this.RCNTDataBits) & oldDataBits & 0x4) == 0x4) {
					//SI fell low, trigger IRQ:
					this.IOCore.irq.requestIRQ(0x80);
				}
			}
		}
		public function readRCNT0() {
			return (this.RCNTDataBitFlow << 4) | this.RCNTDataBits;
		}
		public function writeRCNT1(data) {
			this.RCNTMode = data >> 6;
			this.RCNTIRQ = ((data & 0x1) == 0x1);
			if (this.RCNTMode != 0x2) {
				//Force SI/SO/SC/SD to low as we're never "hooked" up:
				this.RCNTDataBits = 0;
				this.RCNTDataBitFlow = 0;
			}
		}
		public function readRCNT1() {
			return (this.RCNTMode << 6) | 0x3E | ((this.RCNTIRQ) ? 0x1 : 0);
		}
		public function writeJOYCNT(data) {
			this.JOYBUS_IRQ = ((data & 0x40) == 0x40);
			this.JOYBUS_CNTL_FLAGS &= ~(data & 0x7);
		}
		public function readJOYCNT() {
			return 0xB8 | ((this.JOYBUS_IRQ) ? 0x40 : 0) | this.JOYBUS_CNTL_FLAGS;
		}
		public function writeJOYBUS_RECV0(data) {
			this.JOYBUS_RECV0 = data;
		}
		public function readJOYBUS_RECV0() {
			this.JOYBUS_STAT &= 0xF7;
			return this.JOYBUS_RECV0;
		}
		public function writeJOYBUS_RECV1(data) {
			this.JOYBUS_RECV1 = data;
		}
		public function readJOYBUS_RECV1() {
			this.JOYBUS_STAT &= 0xF7;
			return this.JOYBUS_RECV1;
		}
		public function writeJOYBUS_RECV2(data) {
			this.JOYBUS_RECV2 = data;
		}
		public function readJOYBUS_RECV2() {
			this.JOYBUS_STAT &= 0xF7;
			return this.JOYBUS_RECV2;
		}
		public function writeJOYBUS_RECV3(data) {
			this.JOYBUS_RECV3 = data;
		}
		public function readJOYBUS_RECV3() {
			this.JOYBUS_STAT &= 0xF7;
			return this.JOYBUS_RECV3;
		}
		public function writeJOYBUS_SEND0(data) {
			this.JOYBUS_SEND0 = data;
			this.JOYBUS_STAT |= 0x2;
		}
		public function readJOYBUS_SEND0() {
			return this.JOYBUS_SEND0;
		}
		public function writeJOYBUS_SEND1(data) {
			this.JOYBUS_SEND1 = data;
			this.JOYBUS_STAT |= 0x2;
		}
		public function readJOYBUS_SEND1() {
			return this.JOYBUS_SEND1;
		}
		public function writeJOYBUS_SEND2(data) {
			this.JOYBUS_SEND2 = data;
			this.JOYBUS_STAT |= 0x2;
		}
		public function readJOYBUS_SEND2() {
			return this.JOYBUS_SEND2;
		}
		public function writeJOYBUS_SEND3(data) {
			this.JOYBUS_SEND3 = data;
			this.JOYBUS_STAT |= 0x2;
		}
		public function readJOYBUS_SEND3() {
			return this.JOYBUS_SEND3;
		}
		public function writeJOYBUS_STAT(data) {
			this.JOYBUS_STAT = data;
		}
		public function readJOYBUS_STAT() {
			return 0xC5 | this.JOYBUS_STAT;
		}
		public function nextIRQEventTime(clocks) {
			if (this.SIOCNT_IRQ && this.RCNTMode < 2) {
				switch (this.SIOCNT_MODE) {
					case 0:
					case 1:
						if (this.SIOTransferStarted && !this.SIOShiftClockExternal) {
							return ((((this.SIOCNT_MODE == 1) ? 31 : 7) - this.serialBitsShifted) * this.SIOShiftClockDivider) + (this.SIOShiftClockDivider - this.shiftClocks);
						}
						else {
							return -1;
						}
					case 2:
						if (this.SIOTransferStarted && this.SIOMULT_PLAYER_NUMBER == 0) {
							return this.SIOShiftClockDivider - this.shiftClocks;
						}
						else {
							return -1;
						}
					case 3:
						if (this.SIOCNT_UART_SEND_ENABLE && !this.SIOCNT_UART_CTS) {
							return (Math.max(((this.SIOCNT_UART_FIFO_ENABLE) ? (this.SIOCNT_UART_FIFO * 8) : 8) - 1, 0) * this.SIOShiftClockDivider) + (this.SIOShiftClockDivider - this.shiftClocks);
						}
						else {
							return -1;
						}
				}
			}
			else {
				return -1;
			}
		}
		
		
		

	}
	
}