41 lines
916 B
Coq
41 lines
916 B
Coq
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/*
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* This is a simple test of a generate loop.
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*/
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module main;
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parameter SIZE = 4;
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wire [SIZE:0] cin;
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reg [SIZE-1:0] a, b;
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wire [SIZE-1:0] q;
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// This generates a ripple adder by using a generate loop to
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// instantiate an array of half-adders.
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genvar i;
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assign cin[0] = 0;
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for (i=0 ; i<SIZE ; i = i+1) begin : slice
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wire [1:0] sum = a[i] + b[i] + cin[i];
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assign q[i] = sum[0];
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assign cin[i+1] = sum[1];
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end
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wire [SIZE:0] total = {cin[SIZE], q};
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// Test the ripple adder by finding all the possible sums.
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reg [2*SIZE:0] idx;
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initial begin
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for (idx = 0 ; idx < (1<<(2*SIZE)) ; idx = idx+1) begin
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a = idx[ SIZE-1: 0];
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b = idx[2*SIZE-1:SIZE];
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#1 if (total !== a+b) begin
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$display("FAILED -- total=%b, a=%b, b=%b", total, a, b);
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$finish;
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end
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end
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$display("PASSED");
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end
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endmodule
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