Audio_Chip_Init.v

module Audio_Chip_Init
(
input rst, 
input CLOCK_50,
input audioInitPulse, 
inout SDAT,
output SDCLK,
output reg audio_init_done, 
input send,
input[6:0] register,
input[8:0] data,
output reg send_done,
output reg [3:0]audio_init_err
);
parameter ADDRESS = 7'b0011010;
reg [6:0]REGISTERS[0:5];
reg [8:0]DATA[0:5];

reg [3:0]currentInit;
reg [2:0]initState;


//i2c interface
reg i2cEnable;
initial i2cEnable = 1'b0;

reg [6:0]i2cRegister;
reg [8:0]i2cData;
wire [3:0]i2cError;
wire i2cDone;

i2c myI2c( i2cEnable,
	CLOCK_50,
	ADDRESS,//Same address every time: the sound chip.
	i2cRegister,
	i2cData,
	1'b0,//We're always writing. Can't read from this device.
	i2cError,//This will output an error if something goes wrong.
	SDAT,//This is the i2c data line.
	SDCLK,
	i2cDone//Will go high when i2c is done.
);



always @ (posedge CLOCK_50 or negedge rst)
begin

	if(rst == 1'b0)
		begin
			initState <= 1'b0;
		end
	else
		begin
		
			case(initState)
			
				3'd0:
					begin
					
						DATA[0] <= 9'b0_000_1_0000;//Power *most* on.
						DATA[1] <= 9'b0_0_1_0_1_00_11;//Audio format
						DATA[2] <= 9'b0000_10_000;//DACSEL ON, BYPASS off.
						
						DATA[3] <= 9'b0000_0_0_00_0;//DACMU[te] off
						DATA[4] <= 9'b000000001;//Activate
						DATA[5] <= 9'b0_000_0_0000;//Power all the way on.
						
						REGISTERS[0] <= 7'b0000110;//Power Control
						REGISTERS[1] <= 7'b0000111;//Digital Audio Interface (Audio format)
						REGISTERS[2] <= 7'b0000100;//Analog Audio Path Control (BYPASS, DACSEL)
						
						REGISTERS[3] <= 7'b0000101;//Digital Audio Path Control
						REGISTERS[4] <= 7'b0001001;//Activate Control
						REGISTERS[5] <= 7'b0000110;//Power Control
					
						//Wait for the go signal.
						if(audioInitPulse)
							begin
								initState <= initState + 1'b1;
							end
					end
			
				3'd1:
					begin
					
						i2cEnable <= 1'b1;
						i2cRegister <= REGISTERS[currentInit];
						i2cData <= DATA[currentInit];
					
						//Go to next state to wait
						initState <= initState + 1'b1;
					
					end
				3'd2:
					begin
						
						//Wait for completion
						if(i2cDone)
							begin
								initState <= initState + 1'b1;
							end
						else
							begin
								//Keep waiting
							end
					
					end
				3'd3:
					begin
						
						//Disable i2c.
						i2cEnable <= 1'b0;
						//Do we have more to do?
						if(currentInit < 4'd5)
							begin
								//Setup next register.
								currentInit <= currentInit + 1'b1;
								//Go back to beginning
								initState <= 3'd1;
							end
						else
							begin
								//Stay here forever.
								//"Remove" this module from the circuit too.
								initState = 3'd4;
							end
					
					end
				3'd4:
					begin
						//Stay here forever.
						audio_init_done <= 1'b1;
						send_done <= 1'b0;
						i2cEnable <= 1'b0;
						
						//Unless we want to send data manually...
						if(send == 1'b1)
						begin
						
							//Send i2c data manually.
							i2cEnable <= 1'b1;
							i2cData <= data;
							i2cRegister <= register;
							
							//Go to a wait state.
							initState <= 3'd5;
						end
					end
					
				3'd5:
					begin
						
						if(i2cDone)
						begin
							//Go to a finished state
							initState <= 3'd6;
						end
						
					end
				3'd6:
					begin
						//Done
						i2cEnable <= 1'b0;
						send_done <= 1'b1;
						initState <= 3'd4;
					end
					
				default:
					begin
					
					end
			
			endcase
			
		end

end

always @(*)
 audio_init_err = i2cError;


endmodule