Added cocotb testbench for RAM rtl

testbench/cocotb/Makefile

@@ -20,13 +20,15 @@ include $(shell cocotb-config --makefiles)/Makefile.sim
 		test_mux4to1 	\
 		test_DFF_reg	\
 		test_addSubtractor	\
+		test_RAM	\
 		cleanup
 
 all:	test_microprocessor  \
 		test_mux2to1 	\
 		test_mux4to1	\
 		test_DFF_reg	\
 		test_addSubtractor	\
+		test_RAM	\
 		cleanup		
 
 # TOPLEVEL is the name of the toplevel module in your Verilog or VHDL file
@@ -99,6 +101,18 @@ test_addSubtractor:
 	@echo "VERILOG_SOURCES=$(VERILOG_SOURCES)"
 	$(MAKE) sim TOPLEVEL=$(TOPLEVEL) MODULE=$(MODULE) VERILOG_SOURCES="$(VERILOG_SOURCES)"
 
+test_RAM:
+	$(MAKE) cleanup
+	$(info Running test_RAM...)
+	$(eval TOPLEVEL := RAM)
+	$(eval MODULE := test_RAM)
+
+	@echo "TOPLEVEL=$(TOPLEVEL)"
+	@echo "MODULE=$(MODULE)"
+	@echo "VERILOG_SOURCES=$(VERILOG_SOURCES)"
+	$(MAKE) sim TOPLEVEL=$(TOPLEVEL) MODULE=$(MODULE) VERILOG_SOURCES="$(VERILOG_SOURCES)"
+
+
 cleanup:
 	$(info Cleaning up generated files...)
 	$(RM) -vf *.vvp sim_build/* results.xml

testbench/cocotb/test_RAM.py

@@ -0,0 +1,89 @@
+import cocotb
+from cocotb.triggers import RisingEdge, Timer
+
+
+async def generate_clock(dut, num_cycles=10000):
+    """Generate clock pulses."""
+    for cycle in range(num_cycles):
+        dut.clk.value = 0
+        await Timer(1, units="ns")
+        dut.clk.value = 1
+        await Timer(1, units="ns")
+
+
+async def initialize(dut):
+    dut.DATA_IN.value  = 0
+    dut.ADDR.value  = 0
+    dut.WRITE.value  = 0
+    await Timer(1, units="ns")
+
+
+""" 
+Actual RAM DATA in RTL:
+    RAM[0]  = 8'b10000000;	// IN A
+    RAM[1]  = 8'b00111110;	// STORE A into address 11110
+    RAM[2]  = 8'b10000000;	// IN A
+    RAM[3]  = 8'b00111111;  // STORE A into address 11111
+    RAM[4]  = 8'b00011110;	// LOAD Content of 11110 to A (Load first A to A)
+    RAM[5]  = 8'b01111111;	// SUB A with Content of 11111 (First A - Second A)
+    RAM[6]  = 8'b10110000;  // JUMP to 10000[0] if A equals 0
+    RAM[7]  = 8'b11001100;  // JUMP to 01100[12] if A equals positive (First A > Second A)
+    RAM[8]  = 8'b00011111;  // STORE A into address 11111
+    RAM[9]  = 8'b01111110;	// SUB A with Content of 11110
+    RAM[10] = 8'b00111111;  // STORE A into address 11111
+    RAM[11] = 8'b11000100;	// JUMP to 01100 if A equals positive
+    RAM[12] = 8'b00011110;  // STORE A into address 11110 (Store subtracted A back to original first A location)
+    RAM[13] = 8'b01111111;	// SUB A with Content of 11111 (Second A - subtracted A)
+
+    RAM[14] = 8'b00111110;  // STORE A into address 11110
+    RAM[15] = 8'b11000100;	// JUMP to 00100 if A equals positive
+    RAM[16] = 8'b00011110;	// LOAD Content of 11110 to A
+    RAM[17] = 8'b11111111;  // HALT
+    RAM[30] = 8'b00000000;
+    RAM[31] = 8'b00000000;
+"""
+@cocotb.test()
+async def test_RAM_read(dut):
+    await cocotb.start(generate_clock(dut))  # run the clock "in the background"
+    await initialize(dut)  # Call the initialization function
+
+    dut._log.info("Initialization DONE!")
+    await Timer(5, units="ns")  # wait a bit
+
+    # Read RAM[1] and assert its value
+    dut.DATA_IN.value = 0
+    dut.ADDR.value = 1
+    dut.WRITE.value = 0
+
+    # Wait one more cycle for the ADDR change to take effect
+    await RisingEdge(dut.clk)
+    await RisingEdge(dut.clk)
+    assert dut.DATA_OUT.value == 0x3E, f"Expected 0x3E but got {hex(dut.DATA_OUT.value)}"
+    assert dut.ADDR.value == 1, f"Expected 1 but got {dut.ADDR.value}"
+    assert dut.WRITE.value == 0, f"Expected 0 but got {dut.WRITE.value}"
+
+@cocotb.test()
+async def test_RAM_write_addr_31_with_0xAA_then_readback(dut):
+    await cocotb.start(generate_clock(dut))  # run the clock "in the background"
+    await initialize(dut)  # Call the initialization function
+
+    dut._log.info("Initialization DONE!")
+    await Timer(5, units="ns")  # wait a bit
+
+    # Read RAM[1] and assert its value
+    dut.DATA_IN.value = 0xAA
+    dut.ADDR.value = 31
+    dut.WRITE.value = 1
+
+    # Wait one more cycle for the ADDR change and WRITE to take effect
+    await RisingEdge(dut.clk)
+    await RisingEdge(dut.clk)
+    assert dut.ADDR.value == 31, f"Expected 31 but got {dut.ADDR.value}"
+    assert dut.WRITE.value == 1, f"Expected 1 but got {dut.WRITE.value}"
+
+    dut.WRITE.value = 0
+    await RisingEdge(dut.clk)
+    await RisingEdge(dut.clk)
+    assert dut.DATA_OUT.value == 0xAA, f"Expected 0xAA but got {hex(dut.DATA_OUT.value)}"
+    assert dut.ADDR.value == 31, f"Expected 31 but got {dut.ADDR.value}"
+    assert dut.WRITE.value == 0, f"Expected 0 but got {dut.WRITE.value}"