diff --git a/modules/shifter.sv b/modules/shifter.sv index e55e621..e8917d7 100644 --- a/modules/shifter.sv +++ b/modules/shifter.sv @@ -1,12 +1,15 @@ -module shifter #(width=8)(input logic op[1:0], - input logic[width-1:0] A, input logic[width-1:0] B, +module shifter #(width=8)(input logic [2:0] op, + input logic[width-1:0] A, input logic[width-1:0] C, input logic[$clog2(width)-1:0] B, output logic[width-1:0] OUT_1); always_comb begin case (op) - 00: OUT_1 = A << B; - 01: OUT_1 = A >> B; - 10: OUT_1 = $signed(A) >>> B; + 3'b000: OUT_1 = A << C; + 3'b001: OUT_1 = A >> C; + 3'b011: OUT_1 = $signed(A) >>> C; + 3'b100: OUT_1 = A << B; + 3'b101: OUT_1 = A >> B; + 3'b111: OUT_1 = $signed(A) >>> B; default:; endcase end diff --git a/tests/shifter_tb.sv b/tests/shifter_tb.sv index 24c7945..2a43af6 100644 --- a/tests/shifter_tb.sv +++ b/tests/shifter_tb.sv @@ -1,5 +1,77 @@ -`#include "shifter.sv" - +`include "shifter.sv" module shifter_tb #(width=8)(); + logic [2:0] op; + logic [width-1:0] Y; + logic [width-1:0] A_in; + logic [$clog2(width)-1:0] B_in; + logic [width-1:0] C_in; + logic [2:0] ops[6]; + logic [width-1:0] A[6]; + logic [$clog2(width)-1:0] B[6]; + logic [width-1:0] C[6]; + logic [width-1:0] Y_exp[6]; + + shifter #(width) dut(op, A_in,C_in,B_in,Y); + + integer error_count; + initial begin + // Test left shift by C + ops[0] = 3'b000; + A[0] = {{(width-1){1'b0}}, {1'b1}}; + C[0] = {{(width-1){1'b0}}, {1'b1}}; + B[0] = {width{1'b0}}; + Y_exp[0] = {{(width-2){1'b0}}, {2'b10}}; + + // Test left shift by B + ops[1] = 3'b100; + A[1] = {{(width-1){1'b0}}, {1'b1}}; + C[1] = {{(width-1){1'b0}}, {1'b1}}; + B[1] = {{($clog2(width)-2){1'b0}}, 2'b10}; + Y_exp[1] = {{(width-3){1'b0}}, {3'b100}}; + + // Test Logical right shift by C + ops[2] = 3'b001; + A[2] = {{(width-2){1'b0}}, {2'b10}}; + C[2] = {{(width-1){1'b0}}, {1'b1}}; + B[2] = {width{1'b0}}; + Y_exp[2] = {{(width-1){1'b0}}, {1'b1}}; + + // Test Logical right shift by B + ops[3] = 3'b101; + A[3] = {{(width-1){1'b0}}, {2'b10}}; + C[3] = {{(width-1){1'b0}}, {1'b1}}; + B[3] = {{($clog2(width)-2){1'b0}}, 2'b10}; + Y_exp[3] = {{(width-1){1'b0}}, {1'b0}}; + + // Test arithmetic shift right by C + ops[4] = 3'b011; + A[4] = {{(width-1){1'b1}}, 1'b0}; // -2 + C[4] = {{(width-1){1'b0}}, 1'b1}; // 1 + B[4] = {{(width-2){1'b0}}, 2'b10}; // 2 + Y_exp[4] = {width{1'b1}}; // -1 + + // Test arithmetic shift right by B + ops[5] = 3'b111; + A[5] = {{(width-2){1'b1}}, 2'b00}; // -4 + C[5] = {{(width-1){1'b0}}, 1'b1}; // 1 + B[5] = {{(width-2){1'b0}}, 2'b10}; // 2 + Y_exp[5] = {width{1'b1}}; // -1 + + error_count = 0; + $display("Beginning Shifter tests"); + for (integer N = 0; N < $size(ops); ++N) begin + op = ops[N]; + A_in = A[N]; + B_in = B[N]; + C_in = C[N]; + #1; + if (Y != Y_exp[N]) begin + $display("\t\x1b[38;5;9mShifter(%0d) Op 0b%b(0b%b, 0b%b, 0b%b) produced 0b%b but 0b%b was expected\x1b[m", N, op, A_in, B_in, C_in, Y, Y_exp[N]); + error_count = error_count + 1; + end + end + if (error_count == 0) $display("\x1b[38;5;10mAll Shifter tests passing\x1b[m"); + else $display("\x1b[38;5;9m%0d Shifter test(s) failing\x1b[m", error_count); + end endmodule \ No newline at end of file diff --git a/tests/tests.sv b/tests/tests.sv index 46ea98f..abbdfa4 100644 --- a/tests/tests.sv +++ b/tests/tests.sv @@ -1,4 +1,5 @@ `include "tests/seven_seg_tb.sv" `include "tests/lu_tb.sv" `include "tests/asu_tb.sv" -`include "tests/instruction_classifier_tb.sv" \ No newline at end of file +`include "tests/instruction_classifier_tb.sv" +`include "tests/shifter_tb.sv" \ No newline at end of file