Subversion Repositories spigpio

// RTL program for SPI GPIO -- shift 16 bit register
 
`define		P0_OP		7'b0000000 //0x00
`define		P1_OP		7'b0000001 //0x01
`define		P2_OP		7'b0000010 //0x02
`define		P3_OP		7'b0000011 //0x03
`define		P4_OP		7'b0000100 //0x04
`define		P5_OP		7'b0000101 //0x05
`define		P6_OP		7'b0000110 //0x06
`define		P7_OP		7'b0000111 //0x07
`define		P8_OP		7'b0001000 //0x08
`define		P9_OP		7'b0001001 //0x09
 
`define		P0_P9_OP	7'b0001010 //0x0A
`define		P0_P3_OP	7'b0001011 //0x0B
`define		P4_P7_OP	7'b0001100 //0x0C
`define		P8_P9_OP	7'b0001101 //0x0D
 
`define		PO_P7_IP	7'b0001110 //0x0E	
`define		P8_P9_IP	7'b0001111 //0x0F
 
`define		RAM	        7'b0010011 //0x13
 
module spigpio(clk, cs, sr_in, gpioin, gpioout, sr_out);
 
	input clk, cs;
	input sr_in;
	input [9:0] gpioin;
 
	output sr_out;
	output [9:0] gpioout;
 
	reg [9:0] gpioout;
	reg sr_out;
 
	reg [7:0] ram;
	wire [6:0] addr;
	wire [7:0] data;	
	wire rw;
	reg [15:0] sr;
 
	assign rw = sr[15];	
	assign addr = sr[14:8];
	assign data = sr[7:0];
 
	always@(posedge clk or posedge cs)
	begin
		if (cs == 1'b0)
		begin 
			sr_out <= sr[15];
			sr[15:1] <= sr[14:0];
			sr[0] <= sr_in;
		end 		
 
		if (cs == 1'b1)
		begin 
 
			if (rw == 1'b0)
			begin 
 
				case (addr)
				`P0_OP    : gpioout[0] <= data[0];
				`P1_OP    : gpioout[1] <= data[0];
				`P2_OP    : gpioout[2] <= data[0];
				`P3_OP    : gpioout[3] <= data[0];
				`P4_OP    : gpioout[4] <= data[0];
				`P5_OP    : gpioout[5] <= data[0];
				`P6_OP    : gpioout[6] <= data[0];
				`P7_OP    : gpioout[7] <= data[0];
				`P8_OP    : gpioout[8] <= data[0];
				`P9_OP    : gpioout[9] <= data[0];
 
				`P0_P9_OP : gpioout[9:0] <= {data[0], data[0], data[0], data[0], data[0],
							     data[0], data[0], data[0], data[0], data[0]};
				`P0_P3_OP : gpioout[3:0] <= {data[0], data[0], data[0], data[0]};
				`P4_P7_OP : gpioout[7:4] <= {data[0], data[0], data[0], data[0]};
				`P8_P9_OP : gpioout[9:8] <= {data[0], data[0]};
				`RAM      : ram[7:0] <= data[7:0];					
				endcase	
			end
 
			if (rw == 1'b1)             // READ THE PORT LEVEL
			begin 
 
				case (addr)
				`P0_OP	  : sr[7:0] <= {7'b0, gpioout[0]};
				`P1_OP    : sr[7:0] <= {7'b0, gpioout[1]};
				`P2_OP    : sr[7:0] <= {7'b0, gpioout[2]};
				`P3_OP    : sr[7:0] <= {7'b0, gpioout[3]};
				`P4_OP    : sr[7:0] <= {7'b0, gpioout[4]};
				`P5_OP    : sr[7:0] <= {7'b0, gpioout[5]};
				`P6_OP    : sr[7:0] <= {7'b0, gpioout[6]};
				`P7_OP    : sr[7:0] <= {7'b0, gpioout[7]};
				`P8_OP    : sr[7:0] <= {7'b0, gpioout[8]};
				`P9_OP    : sr[7:0] <= {7'b0, gpioout[9]};
				`P0_P9_OP : sr[7:0] <= {7'b0, gpioout[0]};
				`P0_P3_OP : sr[7:0] <= {7'b0, gpioout[0]};
				`P4_P7_OP : sr[7:0] <= {7'b0, gpioout[4]};
				`P8_P9_OP : sr[7:0] <= {7'b0, gpioout[8]};
				`PO_P7_IP : sr[7:0] <= gpioin[7:0];
				`P8_P9_IP : sr[7:0] <= gpioin[9:8];
				`RAM 	  : sr[7:0] <= ram[7:0];						
				endcase
			end
	 	end
	end
endmodule