initial commit

rtl/src/sdspi_testbench.v

@@ -0,0 +1,199 @@
+`timescale 1ns / 1ns
+`default_nettype none
+
+module sdspi_testbench();
+    parameter CLOCK_NS = 10;
+    integer i,j;
+
+    reg[7:0] rx_testdata[0:3];
+    reg[7:0] read_data;
+
+   // Test signals
+    reg clk = 0;
+    reg reset = 0;
+   
+    reg[7:0] tx_data = 0;
+    wire[7:0] rx_data;
+    wire     tx_ready;
+    wire     tx_empty; 
+    wire     rx_avail;
+    wire     rx_ovr;
+    reg      tx_write = 0;
+    reg      rx_read = 0;
+
+    wire     card_detect;
+    wire     card_changed;
+    wire     card_busy;
+
+    reg      ctrl_write = 0;
+    reg      rx_filter_en = 0;
+    reg      txrx_en = 0;
+    reg      spiclk_f_en = 0;
+    reg      spiclk_div_wr = 0;
+
+    // PMOD connections
+    wire  sd_cs_n;
+    wire  sd_mosi;
+    reg  sd_miso = 1;
+    wire sd_sck;
+    reg  sd_cd = 1;
+
+    // Unit Under Test
+    sdspi UUT (
+        .clk(clk),
+        .reset(reset),
+        .tx_data(tx_data),
+        .rx_data(rx_data),
+        .tx_ready(tx_ready),
+        .tx_empty(tx_empty),
+        .rx_avail(rx_avail),
+        .rx_ovr(rx_ovr),
+        .tx_write(tx_write),
+        .rx_read(rx_read),
+        .card_detect(card_detect),
+        .card_changed(card_changed),
+        .card_busy(card_busy),
+        .ctrl_write(ctrl_write),
+        .rx_filter_en(rx_filter_en),
+        .txrx_en(txrx_en),
+        .spiclk_f_en(spiclk_f_en),
+        .spiclk_div_wr(spiclk_div_wr),
+        .sd_cs_n(sd_cs_n),
+        .sd_mosi(sd_mosi),
+        .sd_miso(sd_miso),
+        .sd_sck(sd_sck),
+        .sd_cd(sd_cd)
+        );
+
+    // testbench clock
+    always
+        #(CLOCK_NS/2) clk <= ~clk;
+
+    initial
+    begin
+        rx_testdata[0] <= 'hFF;
+        rx_testdata[1] <= 'hFF;
+        rx_testdata[2] <= 'hCA;
+        rx_testdata[3] <= 'hFE;
+
+        // issue reset
+        reset = 1'b1;
+        #10
+        reset = 1'b0;
+        #10
+
+        // set clock divider
+        tx_data <= 3;
+        spiclk_div_wr <= 1'b1;
+        #10
+        spiclk_div_wr <= 1'b0;
+        #10
+ 
+        // Card initialization phase,
+        // cycle the clock at least 74 times
+        // while cs is off and mosi is high .
+        // we do 32 cycles
+        spiclk_f_en <= 1'b1;
+        ctrl_write <= 1'b1;
+        #10
+        spiclk_f_en <= 1'b0;
+        ctrl_write <= 1'b0;
+        #10
+        for (i=0; i<32*16; i = i + 1)
+            #10;
+        spiclk_f_en <= 1'b0;
+        ctrl_write <= 1'b1;
+        #10
+        ctrl_write <= 1'b0;
+        #10
+        for (i=0; i<32*16; i = i + 1)
+            #10;
+
+        // Write two bytes
+        tx_data  <= 8'hAB;
+        tx_write <= 1'b1;
+        #10;
+        tx_data  <= 8'hCD;
+        tx_write <= 1'b1;
+        #10;
+        tx_write <= 1'b0;
+        #10
+
+        // start transceiver, enable rx_filter
+        txrx_en <= 1'b1;
+        rx_filter_en <= 1'b1;
+        ctrl_write <= 1'b1;
+        #10
+        txrx_en <= 1'b0;
+        rx_filter_en <= 1'b0;
+        ctrl_write <= 1'b0;
+
+        for (i = 0; i < 2048; i = i + 1)
+        begin
+            if (!sd_cs_n && (i % 16)==15) sd_miso <= rx_testdata[(i/(16*8)) % 4][7 - (i/16 % 8)];
+            #10;
+        end
+        tx_write <= 1'b0;
+        #10
+
+        // read from rx fifo
+        read_data <= rx_data;
+        #10
+        $display("read data 1: %02h", read_data);
+
+
+        // strobe rx_read to go to next byte
+        rx_read <= 1'b1;
+        #10  // one cycle to transfer the data
+        rx_read <= 1'b0;
+        #10  // we need this extra cycle for the fifo tail to move
+
+        read_data <= rx_data;
+        #10
+        $display("read data 2: %02h", read_data);
+
+        // strobe rx_read to go to next byte
+        rx_read <= 1'b1;
+        #10
+        rx_read <= 1'b0;
+        #10  // we need this extra cycle for the fifo tail to move
+
+        read_data <= rx_data;
+        #10
+        $display("read data 3: %02h", read_data);
+
+
+        // set flag to turn transceiver off
+        txrx_en <= 1'b0;
+        ctrl_write <= 1'b1;
+        #10
+        ctrl_write <= 1'b0;
+        #10;
+ 
+        // wait for the transceiver to actually turn off
+        for (i=0; i<32*16; i = i + 1)
+            #10;
+
+        #10
+        // clear rx fifo
+        for(i=0; i<14; i = i + 1)
+        begin
+            $display("clear fifo data %02h", rx_data);
+            rx_read <= 1'b1;
+            #10
+            rx_read <= 1'b0;
+            #10
+            #10
+            #10;     // simulate the four cycles of an instruction
+        end
+
+        $finish();
+    end
+
+    initial 
+    begin
+    // Required to dump signals
+    $dumpfile("sdspi_tb_dump.vcd");
+    $dumpvars(0);
+    end
+endmodule