计算机组成原理COP2000课设原码一位乘

最新推荐文章于 2023-03-13 10:34:52 发布

&小鹏鹏

最新推荐文章于 2023-03-13 10:34:52 发布

阅读量5.6k

点赞数 4

CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/u012785169/article/details/44059427

本文介绍了一个8位乘法器的汇编语言实现过程。通过一系列循环和位操作指令，展示了如何将两个8位数值相乘，并将结果存储在两个8位寄存器中。该算法涉及位移、加法及条件跳转等基本操作。

MOV R0,#0B6H           ;被乘数  
MOV R1,#8DH            ;乘数
MOV R2,#00H            ;高位
MOV R3,#00H            ;低位

LOOP1:
      MOV A,R1
      AND A,#01H
      JZ LOOP2
      MOV A,R0
      ADDC A,R3
      JC NEXT1
      MOV R3,A
      JMP LOOP2
      NEXT1:
            MOV R3,A
            MOV A,R2
            ADD A,#01H
            MOV R2,A
LOOP2:
      MOV A,R1
      AND A,#02H
      JZ LOOP3
      MOV A,R0
      AND A,#80H
      RR A
      RR A
      RR A
      RR A
      RR A
      RR A
      RR A
      ADD A,R2
      MOV R2,A
      MOV A,R0
      AND A,#7FH
      RL A
      ADDC A,R3
      JC NEXT2
      MOV R3,A
      JMP LOOP3
      NEXT2:
            MOV R3,A
            MOV A,R2
            ADD A,#01H
            MOV R2,A
      
LOOP3:
      MOV A,R1
      AND A,#04H
      JZ LOOP4
      MOV A,R0
      AND A,#0C0H
      RR A
      RR A
      RR A
      RR A
      RR A
      RR A
      ADD A,R2
      MOV R2,A
      MOV A,R0
      AND A,#3FH
      RL A
      RL A
      ADDC A,R3
      JC NEXT3
      MOV R3,A
      JMP LOOP4
      NEXT3:
            MOV R3,A
            MOV A,R2
            ADD A,#01H
            MOV R2,A
LOOP4:
      MOV A,R1
      AND A,#08H
      JZ LOOP5
      MOV A,R0
      AND A,#0E0H
      RR A
      RR A
      RR A
      RR A
      RR A
      ADD A,R2
      MOV R2,A
      MOV A,R0
      AND A,#1FH
      RL A
      RL A
      RL A
      ADDC A,R3
      JC NEXT4
      MOV R3,A
      JMP LOOP5
      NEXT4:
            MOV R3,A
            MOV A,R2
            ADD A,#01H
            MOV R2,A     
LOOP5:
      MOV A,R1
      AND A,#10H
      JZ LOOP6
      MOV A,R0
      AND A,#0F0H
      RR A
      RR A
      RR A
      RR A
      ADD A,R2
      MOV R2,A
      MOV A,R0
      AND A,#0FH
      RL A
      RL A
      RL A
      RL A
      ADDC A,R3
      JC NEXT5
      MOV R3,A
      JMP LOOP6
      NEXT5:
            MOV R3,A
            MOV A,R2
            ADD A,#01H
            MOV R2,A
LOOP6:
      MOV A,R1
      AND A,#20H
      JZ LOOP7
      MOV A,R0
      AND A,#0F8H
      RR A
      RR A
      RR A
      ADD A,R2
      MOV R2,A
      MOV A,R0
      AND A,#07H
      RL A
      RL A
      RL A
      RL A
      RL A
      ADDC A,R3
      JC NEXT6
      MOV R3,A
      JMP LOOP7
      NEXT6:
            MOV R3,A
            MOV A,R2
            ADD A,#01H
            MOV R2,A

LOOP7:
      MOV A,R1
      AND A,#40H
      JZ LOOP8
      MOV A,R0
      AND A,#0FCH
      RR A
      RR A
      ADD A,R2
      MOV R2,A
      MOV A,R0
      AND A,#03H
      RL A
      RL A
      RL A
      RL A
      RL A
      RL A
      ADDC A,R3
      JC NEXT7
      MOV R3,A
      JMP LOOP7
      NEXT7:
            MOV R3,A
            MOV A,R2
            ADD A,#01H
            MOV R2,A

LOOP8:
      MOV A,R1
      AND A,#80H
      JZ NEXT
      MOV A,R0
      AND A,#0FEH
      RR A
      ADD A,R2
      MOV R2,A
      MOV A,R0
      AND A,#01H
      RL A
      RL A
      RL A
      RL A
      RL A
      RL A
      RL A
      ADDC A,R3
      JC NEXT8
      MOV R3,A
      JMP NEXT
      NEXT8:
            MOV R3,A
            MOV A,R2
            ADD A,#01H
            MOV R2,A  
NEXT:JMP NEXT