SAP-1 (Simple As Possible 1) Microprocessor – Part 4

The Testbench and Results

The test program was stored in RAM of SAP-1 microprocessor,

• Load contents of memory location 9H into accumulator
  • 9H contains 01H. Accumulator is loaded with 01H
• Add the contents of AH.
  • AH contains 02H. Result is 03H
• Add the contents of BH.
  • BH contians 03H. Result is 06H
• Subtract the result by the contents of CH.
  • CH containes 04H. Result is 02H
• OUT and Halt (two instructions)
  • Output the result

`timescale 1ns/1ps


module tb();

reg clk;
reg clr;
wire [7:0] result;

always begin
    #5 clk=~clk;
    end

initial begin
    $dumpfile("sap1tb.vcd");
    $dumpvars(0,sap1tb);

    clk=0;
    clr=1;

    #50
    clr=0;

    #5
    clr=1;

    #310 $finish;
    end

sap1 sap1tb(clk,clr,result);

endmodule

Output Waveforms

http://bshashidhar.com/wp-content/uploads/2016/09/op.jpg