54 lines
1.4 KiB
Verilog
54 lines
1.4 KiB
Verilog
// femtorv32, a minimalistic RISC-V RV32I core
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// Bruno Levy, 2020-2021
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//
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// This file: driver for LEDs (does nearly nothing !)
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//
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module LEDDriver(
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`ifdef NRV_IO_IRDA
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output wire irda_TXD,
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input wire irda_RXD,
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output wire irda_SD,
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`endif
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input wire clk, // system clock
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input wire rstrb, // read strobe
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input wire wstrb, // write strobe
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input wire sel, // select (read/write ignored if low)
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input wire [31:0] wdata, // data to be written
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output wire [31:0] rdata, // read data
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output wire [3:0] LED // LED pins
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);
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// The IceStick has an infrared reveiver/transmitter pair
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// See EXAMPLES/test_ir_sensor.c and EXAMPLES/test_ir_remote.c
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`ifdef NRV_IO_IRDA
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reg [5:0] led_state;
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assign LED = led_state[3:0];
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assign rdata = (sel ? {25'b0, irda_RXD, led_state} : 32'b0);
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assign irda_SD = led_state[5];
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assign irda_TXD = led_state[4];
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`else
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reg [3:0] led_state;
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assign LED = led_state;
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initial begin
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led_state = 4'b0000;
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end
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assign rdata = (sel ? {28'b0, led_state} : 32'b0);
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`endif
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always @(posedge clk) begin
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if(sel && wstrb) begin
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`ifdef NRV_IO_IRDA
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led_state <= wdata[5:0];
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`else
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led_state <= wdata[3:0];
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`endif
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`ifdef BENCH
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$display("****************** LEDs = %b", wdata[3:0]);
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`endif
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end
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end
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endmodule
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