四、 仿真结果与波形
LAB 8：通过模块间的调用实现自顶向下CPU的是设计
一、 二、
实验目的 实验原理
学习和使用层次化、结构化设计方法。
Verilog HDL中，上层模块引用下层模块与C语言中程序调用有些类似，被引用的子模块在综合时作为其父模块的一部分被综合，形成相应的电路结构。在进行模块实例引用时，必须注意的是模块之间对应的端口，即子模块端口与父模块的内部信号必须是一一对应。
三、 源代码
CPUtest1.dat
//opcode_operand // addr assembly code //-------------- // ---- ----------------------------------------------- @00 111_11110 // 00 BEGIN: JMP TST_JMP
000_00000 // 01 HLT //JMP did not work at all
000_00000 // 02 HLT //JMP did not load PC, it skipped
101_11010 // 03 JMP_OK: LDA DATA_1 001_00000 // 04 SKZ
000_00000 // 05 HLT //SKZ or LDA did not work 101_11011 // 06 LDA DATA_2 001_00000 // 07 SKZ
111_01010 // 08 JMP SKZ_OK
000_00000 // 09 HLT //SKZ or LDA did not work 110_11100 // 0A SKZ_OK: STO TEMP //store non-zero value in TEMP
101_11010 // 0B LDA DATA_1
110_11100 // 0C STO TEMP //store zero value in TEMP 101_11100 // 0D LDA TEMP
001_00000 // 0E SKZ //check to see if STO worked 000_00000 // 0F HLT //STO did not work 100_11011 // 10 XOR DATA_2
001_00000 // 11 SKZ //check to see if XOR worked 111_10100 // 12 JMP XOR_OK
000_00000 // 13 HLT //XOR did not work at all 100_11011 // 14 XOR_OK: XOR DATA_2 001_00000 // 15 SKZ
000_00000 // 16 HLT //XOR did not switch all bits 000_00000 // 17 END: HLT //CONGRATULATIONS - TEST1 PASSED!
111_00000 // 18 JMP BEGIN //run test again
@1A 00000000 // 1A DATA_1: //constant 00(hex) 11111111 // 1B DATA_2: //constant FF(hex)
10101010 // 1C TEMP: //variable - inititially AA(hex)
@1E 111_00011 // 1E TST_JMP: JMP JMP_OK
000_00000 // 1F HLT //JMP is broken
CPUtest2.dat
//opcode_operand // addr assembly code //-------------- // ---- ----------------------------------------------- @00 101_11011 // 00 BEGIN: LDA DATA_2 011_11100 // 01 AND DATA_3 100_11011 // 02 XOR DATA_2 001_00000 // 03 SKZ
000_00000 // 04 HLT //AND doesn't work 010_11010 // 05 ADD DATA_1 001_00000 // 06 SKZ
111_01001 // 07 JMP ADD_OK
000_00000 // 08 HLT //ADD doesn't work 100_11100 // 09 XOR DATA_3
010_11010 // 0A ADD DATA_1 //FF plus 1 makes -1 110_11101 // 0B STO TEMP 101_11010 // 0C LDA DATA_1
010_11101 // 0D ADD TEMP //-1 plus 1 should make zero
001_00000 // 0E SKZ
000_00000 // 0F HLT //ADD Doesn't work
000_00000 // 10 END: HLT //CONGRATULATIONS - TEST2 PASSED!
111_00000 // 11 JMP BEGIN //run test again
@1A 00000001 // 1A DATA_1: //constant 1(hex) 10101010 // 1B DATA_2: //constant AA(hex) 11111111 // 1C DATA_3: //constant FF(hex) 00000000 // 1D TEMP:
CPUtest3.dat
//opcode_operand // addr assembly code //-------------- // ---- ----------------------------------------------------
111_00011 // 00 JMP LOOP //jump to the address of LOOP
@03 101_11011 // 03 LOOP: LDA FN2 //load value in FN2 into accum
110_11100 // 04 STO TEMP //store accumulator in TEMP
010_11010 // 05 ADD FN1 //add value in FN1 to accumulator
110_11011 // 06 STO FN2 //store result in FN2
101_11100 // 07 LDA TEMP //load TEMP into the accumulator
110_11010 // 08 STO FN1 //store accumulator in FN1 100_11101 // 09 XOR LIMIT //compare accumulator to LIMIT
001_00000 // 0A SKZ //if accum = 0, skip to DONE 111_00011 // 0B JMP LOOP //jump to address of LOOP 000_00000 // 0C DONE: HLT //end of program 101_11111 // 0D AGAIN: LDA ONE 110_11010 // 0E STO FN1 101_11110 // 0F LDA ZERO 110_11011 // 10 STO FN2
111_00011 // 11 JMP LOOP //jump to address of LOOP
@1A 00000001 // 1A FN1: //variable - stores 1st Fib. No. 00000000 // 1B FN2: //variable - stores 2nd Fib. No. 00000000 // 1C TEMP: //temporary variable
10010000 // 1D LIMIT: //constant 144 - max value 00000000 // 1E ZERO: //constant 0 00000001 // 1F ONE: //constant 1
CPUtest4.dat 自己编写的CPUtest，实现乘法器
//opcode_operand // addr assembly code //-------------- // ---- ----------------------------------------------------
@03 111_00100 // 03 JMP LOOP //jump to the address of LOOP 101_11011 // 04 LOOP: LDA DATA2 //A=5 010_11010 // 05 ADD DATA1 //A=5+5=10 110_11011 // 06 STO DATA2 //DATA2=10 101_11101 // 07 LDA TIME //A=TIME 011_11111 // 08 AND TIME //A =TIME 010_11100 // O9 ADD TEMP //A=TIME+1 110_11101 // 0A STO TIME //TIME=TIME+1
100_11110 // 0B XOR LIMIT //compare accumulator to LIMIT
001_00000 // 0C SKZ //if accum = 0, skip to DONE 111_00100 // 0D JMP LOOP //jump to address of LOOP 000_00000 // 0E DONE: HLT //end of program
@1A 00000101 // 1A data1: //5 variable - stores 1st Fib. No.