From 103aa769fdc30721311396415843971ec09b9512 Mon Sep 17 00:00:00 2001
From: Riley King-Saunders <riley.kingsaunders@gmail.com>
Date: Fri, 16 Oct 2026 03:53:14 +1100
Subject: [PATCH] Added testbench for MIPS processor

---
 tests/mips-rtype.sv |  6 ---
 tests/mips.sv       | 95 +++++++++++++++++++++++++++++++++++++++++++++
 tests/tests.sv      |  3 +-
 3 files changed, 97 insertions(+), 7 deletions(-)
 delete mode 100644 tests/mips-rtype.sv
 create mode 100644 tests/mips.sv

diff --git a/tests/mips-rtype.sv b/tests/mips-rtype.sv
deleted file mode 100644
index 36608c0..0000000
--- a/tests/mips-rtype.sv
+++ /dev/null
@@ -1,6 +0,0 @@
-`include "assignment2.sv"
-
-
-module mips_rtype_tb(input logic [0:0] clk);
-    assignment2 #(5) CPU (clk);
-endmodule
\ No newline at end of file
diff --git a/tests/mips.sv b/tests/mips.sv
new file mode 100644
index 0000000..08e6928
--- /dev/null
+++ b/tests/mips.sv
@@ -0,0 +1,95 @@
+`include "assignment2.sv"
+
+`define PRINT_REGISTERS(regs)\
+    $display("\tt0-t8: \t0x%0x 0x%0x 0x%0x 0x%0x 0x%0x 0x%0x 0x%0x 0x%0x\n\ts0-s8: \t0x%0x 0x%0x 0x%0x 0x%0x 0x%0x 0x%0x 0x%0x 0x%0x\n",\
+        regs[8], regs[9], regs[10], regs[11], regs[12], regs[13], regs[14], regs[15],   \
+        regs[16], regs[17], regs[18], regs[19], regs[20], regs[21], regs[22], regs[23]  \
+    );
+`define TEST_CHECK(cond) if (cond) begin end else begin   \
+        $display("Check %s failed\n", `"cond`");          \
+        `PRINT_REGISTERS(CPU.REGS.regs);                  \
+        num_errors += 1;                                  \
+    end
+
+module mips_tb(input logic [0:0] clk);
+    assignment2 #(5, 9, 10) CPU (clk);
+
+    integer num_errors = 0;
+    initial begin
+        // Zero out lower registers
+        $display("Beginning MIPS tests");
+        assign num_errors = 0;
+
+        for (integer N = 1; N < 32; ++N)
+            CPU.REGS.regs[N] = 32'd0;
+
+        // Check R-type / initialise
+        #1;
+        `TEST_CHECK(CPU.REGS.regs[8] == 32'd0);
+        #1;
+        `TEST_CHECK(CPU.REGS.regs[9] == (CPU.REGS.regs[8] + 32'd7));
+
+        // Check load-store
+        #1;
+        `TEST_CHECK(CPU.RAM.mem[0] == CPU.REGS.regs[9]);
+        #1;
+        `TEST_CHECK(CPU.REGS.regs[10] == CPU.RAM.mem[0]);
+
+        // Check arithmetic
+        #1;
+        `TEST_CHECK(CPU.REGS.regs[11] == (CPU.REGS.regs[9] + CPU.REGS.regs[10]));
+        #1;
+        `TEST_CHECK(CPU.REGS.regs[12] == (CPU.REGS.regs[9] - CPU.REGS.regs[11]));
+        #1;
+        `TEST_CHECK(CPU.REGS.regs[13] == (CPU.REGS.regs[9] + 3));
+        #1;
+        `TEST_CHECK(CPU.REGS.regs[14] == (CPU.REGS.regs[12] + CPU.REGS.regs[13]));
+
+        // Check logic instructions
+        #1;
+        `TEST_CHECK(CPU.REGS.regs[16] == (CPU.REGS.regs[9] & CPU.REGS.regs[13]));
+        #1;
+        `TEST_CHECK(CPU.REGS.regs[17] == (CPU.REGS.regs[9] | CPU.REGS.regs[13]));
+        #1;
+        `TEST_CHECK(CPU.REGS.regs[18] == (CPU.REGS.regs[9] ^ CPU.REGS.regs[13]));
+        #1;
+        `TEST_CHECK(CPU.REGS.regs[19] == ( ~(CPU.REGS.regs[9] | CPU.REGS.regs[13]) ));
+
+        // Check SLT instructions
+        #1;
+        `TEST_CHECK(CPU.REGS.regs[20] == $signed(CPU.REGS.regs[12]) < $signed(CPU.REGS.regs[14]));
+        #1;
+        `TEST_CHECK(CPU.REGS.regs[21] == $unsigned(CPU.REGS.regs[12]) < $unsigned(CPU.REGS.regs[14]));
+        
+        // Check loop branching
+        for (integer N = 1; N < 11; ++N) begin
+            #1;
+            `TEST_CHECK(CPU.REGS.regs[0] == 32'(N));
+            #1;
+            `TEST_CHECK(CPU.REGS.regs[22] == $unsigned(CPU.REGS.regs[8]) < $unsigned(CPU.REGS.regs[13]));
+        end
+
+        // Final state check
+        #1;
+        `TEST_CHECK(CPU.REGS.regs[8]  == 32'd10);
+        `TEST_CHECK(CPU.REGS.regs[9]  == 32'd7);
+        `TEST_CHECK(CPU.REGS.regs[10] == 32'd7);
+        `TEST_CHECK(CPU.REGS.regs[11] == 32'd14);
+        `TEST_CHECK(CPU.REGS.regs[12] == -32'sd7);
+        `TEST_CHECK(CPU.REGS.regs[13] == 32'd10);
+        `TEST_CHECK(CPU.REGS.regs[14] == 32'd3);
+        `TEST_CHECK(CPU.REGS.regs[15] == 32'd0);
+        
+        `TEST_CHECK(CPU.REGS.regs[16] == 32'd2);
+        `TEST_CHECK(CPU.REGS.regs[17] == 32'd15);
+        `TEST_CHECK(CPU.REGS.regs[18] == 32'd13);
+        `TEST_CHECK(CPU.REGS.regs[19] == -32'sd16);
+        `TEST_CHECK(CPU.REGS.regs[20] == 32'd1);
+        `TEST_CHECK(CPU.REGS.regs[21] == 32'd0);
+        `TEST_CHECK(CPU.REGS.regs[22] == 32'd0);
+        `TEST_CHECK(CPU.REGS.regs[23] == 32'd0);
+
+        if (num_errors == 0) $display("\x1b[38;5;10mAll MIPS tests passing\x1b[m");
+        else $display("\x1b[38;5;9m%0d MIPS test(s) failing\x1b[m", num_errors);
+    end
+endmodule
\ No newline at end of file
diff --git a/tests/tests.sv b/tests/tests.sv
index 88cba1d..48fa8ed 100644
--- a/tests/tests.sv
+++ b/tests/tests.sv
@@ -3,4 +3,5 @@
 `include "tests/asu_tb.sv"
 `include "tests/instruction_classifier_tb.sv"
 `include "tests/shifter_tb.sv"
-`include "tests/alu_tb.sv"
\ No newline at end of file
+`include "tests/alu_tb.sv"
+`include "tests/mips.sv"
\ No newline at end of file