diff --git a/modules/alu.sv b/modules/alu.sv index 08aac74..c3516ce 100644 --- a/modules/alu.sv +++ b/modules/alu.sv @@ -1,3 +1,6 @@ +`ifndef ALU_H_SV +`define ALU_H_SV + `include "asu.sv" `include "lu.sv" @@ -5,8 +8,9 @@ // flags[1:1] = Overflow module alu #(parameter width=2)(input logic [3:0] op, input logic [2**width-1:0] A, input logic [2**width-1:0] B, - output logic [2**width-1:0] OUT_1, output logic flags[1:0]); + output logic [2**width-1:0] OUT_1, output logic[1:0] flags); + logic [0:0] asu_op; logic [2**width-1:0] asu_out; logic [1:0] asu_flags; asu #(width) adder_unit(asu_op[op[1]], A, B, asu_out, asu_flags[0], asu_flags[1]); @@ -16,17 +20,18 @@ module alu #(parameter width=2)(input logic [3:0] op, always_comb begin case (op) - 2'b0000: begin OUT_1 = asu_out; flags = asu_flags; end - 2'b0001: begin OUT_1 = asu_out; flags = asu_flags; end - 2'b0010: begin OUT_1 = asu_out; flags = asu_flags; end - 2'b0011: begin OUT_1 = asu_out; flags = asu_flags; end - 2'b0100: OUT_1 = lu_out; - 2'b0101: OUT_1 = lu_out; - 2'b0110: OUT_1 = lu_out; - 2'b0111: OUT_1 = lu_out; - 2'b1010: OUT_1 = (asu_out[2**width-1] ^ asu_flags[1]); - 2'b1011: OUT_1 = ~asu_flags[0]; - default: '0; + 4'b0000: begin OUT_1 = asu_out; flags = asu_flags; end + 4'b0001: begin OUT_1 = asu_out; flags = asu_flags; end + 4'b0010: begin OUT_1 = asu_out; flags = asu_flags; end + 4'b0011: begin OUT_1 = asu_out; flags = asu_flags; end + 4'b0100: OUT_1 = lu_out; + 4'b0101: OUT_1 = lu_out; + 4'b0110: OUT_1 = lu_out; + 4'b0111: OUT_1 = lu_out; + 4'b1010: OUT_1 = (asu_out[2**width-1] ^ asu_flags[1]) & {{(width-1){1'b0}}, 1'b1}; + 4'b1011: OUT_1 = ~asu_flags[0] & {{(width-1){1'b0}}, 1'b1}; + default: OUT_1 = {(2**width){1'b0}}; endcase end -endmodule \ No newline at end of file +endmodule +`endif \ No newline at end of file diff --git a/tests/alu_tb.sv b/tests/alu_tb.sv index fd7d300..4c4ef15 100644 --- a/tests/alu_tb.sv +++ b/tests/alu_tb.sv @@ -1,33 +1,211 @@ -`#include "alu.sv" +`include "alu.sv" module alu_tb #(width=2)(); + localparam bitwidth = 2**width; + + // Guard against future me by testing the tests + generate + if (bitwidth < 4) begin : param_asserts + initial begin + $fatal(1, "Can not instantiate an ALU testbench with less than 4 bits (n=2)"); + end + end + endgenerate + logic [3:0] op_in; logic [2**width-1:0] A_in; logic [2**width-1:0] B_in; logic [2**width-1:0] Y_out; logic [1:0] flags_out; - logic [3:0] ops[1]; - logic [2**width-1:0] A_cases[$size(ops)]; - logic [2**width-1:0] B_cases[$size(ops)]; - logic [2**width-1:0] Y_exp[$size(ops)]; - logic [1:0] flags_exp[$size(ops)]; + localparam int NUM_TESTS = 28; + logic [3:0] ops[NUM_TESTS]; + logic [2**width-1:0] A_cases[NUM_TESTS]; + logic [2**width-1:0] B_cases[NUM_TESTS]; + logic [2**width-1:0] Y_exp[NUM_TESTS]; + logic [1:0] flags_exp[NUM_TESTS]; - alu #(width)(op_in, A_in, B_in, Y_out, flags_out); + alu #(width) dut (op_in, A_in, B_in, Y_out, flags_out); integer error_count; initial begin + ops[0] = 4'b0000; // sadd + A_in[0] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + B_in[0] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + Y_exp[0] = {{(bitwidth-2){1'b0}}, 2'b10}; // 0 + flags_exp[0] = {2'b00}; // ~Cout, ~Overflow + ops[1] = 4'b0000; // sadd + A_in[1] = {bitwidth{1'b1}}; // UINTMAX + B_in[1] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + Y_exp[1] = {bitwidth{1'b0}}; // 0 + flags_exp[1] = {2'b01}; // Cout, ~Overflow + + ops[2] = 4'b0000; // sadd + A_in[2] = {{1'b0}, {(bitwidth-1){1'b1}}}; // INTMAX + B_in[2] = {{(bitwidth-1){1'b0}} , {1'b1}}; // 1 + Y_exp[2] = {{1'b1}, {(bitwidth-1){1'b0}} };// -INTMAX + flags_exp[2] = {2'b10}; // ~Cout, Overflow + + ops[3] = 4'b0000; // sadd + A_in[3] = {{1'b1}, {(bitwidth-1){1'b0}}}; // -INTMAX + B_in[3] = {{1'b1}, {(bitwidth-1){1'b0}}}; // -INTMAX + Y_exp[3] = {bitwidth{1'b0}}; // 0 + flags_exp[3] = {2'b11}; // Cout, Overflow + + ops[4] = 4'b0001; // uadd + A_in[4] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + B_in[4] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + Y_exp[4] = {{(bitwidth-2){1'b0}}, 2'b10}; // 0 + flags_exp[4] = {2'b00}; // ~Cout, ~Overflow + + ops[5] = 4'b0001; // uadd + A_in[5] = {bitwidth{1'b1}}; // UINTMAX + B_in[5] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + Y_exp[5] = {bitwidth{1'b0}}; // 0 + flags_exp[5] = {2'b01}; // Cout, ~Overflow + + ops[6] = 4'b0001; // uadd + A_in[6] = {{1'b0}, {(bitwidth-1){1'b1}}}; // INTMAX + B_in[6] = {{(bitwidth-1){1'b0}} , {1'b1}}; // 1 + Y_exp[6] = {{1'b1}, {(bitwidth-1){1'b0}} };// -INTMAX + flags_exp[6] = {2'b10}; // ~Cout, Overflow + + ops[7] = 4'b0001; // uadd + A_in[7] = {{1'b1}, {(bitwidth-1){1'b0}}}; // -INTMAX + B_in[7] = {{1'b1}, {(bitwidth-1){1'b0}}}; // -INTMAX + Y_exp[7] = {bitwidth{1'b0}}; // 0 + flags_exp[7] = {2'b11}; // Cout, Overflow + + ops[8] = 4'b0010; // ssub + A_in[8] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + B_in[8] = {{(bitwidth-2){1'b0}}, 2'b10}; // 2 + Y_exp[8] = {bitwidth{1'b1}}; // -1 + flags_exp[8] = {2'b00}; // ~Cout, ~Overflow + + ops[9] = 4'b0010; // ssub + A_in[9] = {1'b0, {(bitwidth-1){1'b1}}}; // INTMAX + B_in[9] = {{(bitwidth-1){1'b0}}, 1'b1}; // -1 + Y_exp[9] = {1'b1, {(bitwidth-1){1'b0}}}; // -INTMAX + flags_exp[9] = {2'b10}; // ~Cout, Overflow + + ops[10] = 4'b0010; // ssub + A_in[10] = {{(bitwidth-2){1'b0}}, 2'b10}; // 2 + B_in[10] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + Y_exp[10] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + flags_exp[10] = {2'b01}; // Cout, ~Overflow + + ops[11] = 4'b0010; // ssub + A_in[11] = {1'b1, {(bitwidth-1){1'b0}}}; // -INTMAX + B_in[11] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + Y_exp[11] = {1'b0, {(bitwidth-1){1'b1}}}; // INTMAX + flags_exp[11] = {2'b11}; // Cout, Overflow + + ops[12] = 4'b0011; // ssub + A_in[12] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + B_in[12] = {{(bitwidth-2){1'b0}}, 2'b10}; // 2 + Y_exp[12] = {bitwidth{1'b1}}; // -1 + flags_exp[12] = {2'b00}; // ~Cout, ~Overflow + + ops[13] = 4'b0011; // ssub + A_in[13] = {1'b0, {(bitwidth-1){1'b1}}}; // INTMAX + B_in[13] = {{(bitwidth-1){1'b0}}, 1'b1}; // -1 + Y_exp[13] = {1'b1, {(bitwidth-1){1'b0}}}; // -INTMAX + flags_exp[13] = {2'b10}; // ~Cout, Overflow + + ops[14] = 4'b0011; // ssub + A_in[14] = {{(bitwidth-2){1'b0}}, 2'b10}; // 2 + B_in[14] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + Y_exp[14] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + flags_exp[14] = {2'b01}; // Cout, ~Overflow + + ops[15] = 4'b0011; // ssub + A_in[15] = {1'b1, {(bitwidth-1){1'b0}}}; // -INTMAX + B_in[15] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + Y_exp[15] = {1'b0, {(bitwidth-1){1'b1}}}; // INTMAX + flags_exp[15] = {2'b11}; // Cout, Overflow + + ops[16] = 4'b0100; // and + A_in[16] = {{(bitwidth-4){1'b0}}, 4'b1100}; // c + B_in[16] = {{(bitwidth-4){1'b0}}, 4'b1010}; // a + Y_exp[16] = {{(bitwidth-4){1'b0}}, 4'b1000}; // 8 + flags_exp[16] = {2'bxx}; // Don't care + + ops[17] = 4'b0101; // or + A_in[17] = {{(bitwidth-4){1'b0}}, 4'b1100}; // c + B_in[17] = {{(bitwidth-4){1'b0}}, 4'b1010}; // a + Y_exp[17] = {{(bitwidth-4){1'b0}}, 4'b1110}; // e + flags_exp[17] = {2'bxx}; // Don't care + + ops[18] = 4'b0110; // xor + A_in[18] = {{(bitwidth-4){1'b0}}, 4'b1100}; // c + B_in[18] = {{(bitwidth-4){1'b0}}, 4'b1010}; // a + Y_exp[18] = {{(bitwidth-4){1'b0}}, 4'b0110}; // 6 + flags_exp[18] = {2'bxx}; // Don't care + + ops[19] = 4'b0111; // nor + A_in[19] = {{(bitwidth-4){1'b0}}, 4'b1100}; // c + B_in[19] = {{(bitwidth-4){1'b0}}, 4'b1010}; // a + Y_exp[19] = {{(bitwidth-4){1'b0}}, 4'b0001}; // 1 + flags_exp[19] = {2'bxx}; // Don't care + + ops[20] = 4'b1010; // sslt: 1 < 2 (No overflow) + A_in[20] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + B_in[20] = {{(bitwidth-2){1'b0}}, 2'b10}; // 2 + Y_exp[20] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 (True) + flags_exp[20] = {2'b00}; // ~Cout, ~Overflow + + ops[21] = 4'b1010; // sslt: 2 < 1 (No overflow) + A_in[21] = {{(bitwidth-2){1'b0}}, 2'b10}; // 2 + B_in[21] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + Y_exp[21] = {bitwidth{1'b0}}; // 0 (False) + flags_exp[21] = {2'b10}; // Cout, ~Overflow + + ops[22] = 4'b1010; // sslt: -INTMAX < 1 (Overflow test) + A_in[22] = {1'b1, {(bitwidth-1){1'b0}}}; // -INTMAX + B_in[22] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + Y_exp[22] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 (True) + flags_exp[22] = {2'b11}; // Cout, Overflow + + ops[23] = 4'b1010; // sslt: INTMAX < -1 (Overflow test) + A_in[23] = {1'b0, {(bitwidth-1){1'b1}}}; // INTMAX + B_in[23] = {bitwidth{1'b1}}; // -1 + Y_exp[23] = {bitwidth{1'b0}}; // 0 (False) + flags_exp[23] = {2'b01}; // ~Cout, Overflow + + ops[24] = 4'b1011; // uslt: 1 < 2 + A_in[24] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + B_in[24] = {{(bitwidth-2){1'b0}}, 2'b10}; // 2 + Y_exp[24] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 (True) + flags_exp[24] = {2'b00}; // ~Cout, ~Overflow + + ops[25] = 4'b1011; // uslt: 2 < 1 + A_in[25] = {{(bitwidth-2){1'b0}}, 2'b10}; // 2 + B_in[25] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + Y_exp[25] = {bitwidth{1'b0}}; // 0 (False) + flags_exp[25] = {2'b10}; // Cout, ~Overflow + + ops[26] = 4'b1011; // uslt: 1 < UINTMAX + A_in[26] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + B_in[26] = {bitwidth{1'b1}}; // UINTMAX + Y_exp[26] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 (True) + flags_exp[26] = {2'b00}; // ~Cout, ~Overflow + + ops[27] = 4'b1011; // uslt: UINTMAX < 1 + A_in[27] = {bitwidth{1'b1}}; // UINTMAX + B_in[27] = {{(bitwidth-1){1'b0}}, 1'b1}; // 1 + Y_exp[27] = {bitwidth{1'b0}}; // 0 (False) + flags_exp[27] = {2'b10}; // Cout, ~Overflow error_count = 0; $display("Beginning ALU tests"); for (integer N = 0; N < $size(ops); ++N) begin - op = ops[N]; + op_in = ops[N]; A_in = A_cases[N]; B_in = B_cases[N]; #1; if (Y_out != Y_exp[N]) begin - $display("\t\x1b[38;5;9mALU Instruction 0b%b produced 0b%b_%b but 0b%b_%b was expected\x1b[m", op, flags_out, Y_out, flags_exp[N], Y_exp[N]); + $display("\t\x1b[38;5;9m[%0d] ALU Instruction 0b%b produced 0b%b_%b but 0b%b_%b was expected\x1b[m", N, op_in, flags_out, Y_out, flags_exp[N], Y_exp[N]); error_count = error_count + 1; end end diff --git a/tests/tests.sv b/tests/tests.sv index abbdfa4..88cba1d 100644 --- a/tests/tests.sv +++ b/tests/tests.sv @@ -2,4 +2,5 @@ `include "tests/lu_tb.sv" `include "tests/asu_tb.sv" `include "tests/instruction_classifier_tb.sv" -`include "tests/shifter_tb.sv" \ No newline at end of file +`include "tests/shifter_tb.sv" +`include "tests/alu_tb.sv" \ No newline at end of file