Update sys.

sys/mcp23009.sv

@@ -0,0 +1,113 @@
+//
+// MCP23009
+// (C) 2019 Alexey Melnikov
+//
+module mcp23009
+(
+	input            clk,
+
+	output reg [2:0] btn,
+	input      [2:0] led,
+	output reg       sd_cd,
+
+	output		     scl,
+	inout 		     sda
+);
+
+
+reg        start = 0;
+wire       ready;
+wire       error;
+reg        rw;
+wire [7:0] dout;
+reg [15:0] din;
+
+i2c #(50_000_000, 500_000) i2c
+(
+	.CLK(clk),
+	.START(start),
+	.READ(rw),
+	.I2C_ADDR('h20),
+	.I2C_WLEN(1),
+	.I2C_WDATA1(din[15:8]),
+	.I2C_WDATA2(din[7:0]),
+	.I2C_RDATA(dout),
+	.END(ready),
+	.ACK(error),
+	.I2C_SCL(scl),
+ 	.I2C_SDA(sda)
+);
+
+always@(posedge clk) begin
+	reg  [3:0] idx = 0;
+	reg  [1:0] state = 0;
+	reg [15:0] timeout = 0;
+
+	if(~&timeout) begin
+		timeout <= timeout + 1'd1;
+		start   <= 0;
+		state   <= 0;
+		idx     <= 0;
+		btn     <= 0;
+		rw      <= 0;
+		sd_cd   <= 1;
+	end
+	else begin
+		if(~&init_data[idx]) begin
+			case(state)
+			0:	begin
+					start <= 1;
+					state <= 1;
+					din   <= init_data[idx];
+				end
+			1: if(~ready) state <= 2;
+			2:	begin
+					start <= 0;
+					if(ready) begin
+						state <= 0;
+						if(!error) idx <= idx + 1'd1;
+					end
+				end
+			endcase
+		end
+		else begin
+			case(state)
+			0:	begin
+					start <= 1;
+					state <= 1;
+					din   <= {8'h09,5'b00000,led};
+				end
+			1: if(~ready) state <= 2;
+			2:	begin
+					start <= 0;
+					if(ready) begin
+						state <= 0;
+						rw <= 0;
+						if(!error) begin
+							if(rw) {sd_cd, btn} <= {dout[7], dout[5:3]};
+							rw <= ~rw;
+						end
+					end
+				end
+			endcase
+		end
+	end
+end
+
+wire [15:0] init_data[12] = 
+'{
+	16'h00F8,
+	16'h0138,
+	16'h0200,
+	16'h0300,
+	16'h0400,
+	16'h0524,
+	16'h06FF,
+	16'h0700,
+	16'h0800,
+	16'h0900,
+	16'h0A00,
+	16'hFFFF
+};
+
+endmodule