MacPlus_MiSTer/sys/mcp23009.sv

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2019-09-27 17:11:21 +00:00
//
// 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