产生随机数_汇编

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1、1、keil中的rand函数反编译结果：/*  TEST.c                            */#includevoidmain(void){    CHARi,j,k;    i=0x5f;    j=rand();    k=0xf5;}反编译结果，随机数放在R7中;==========================================================================Q0003:             MOV   R4,08H                       ;000

2、3   AC08                   MOV   R5,09H                       ;0005   AD09                   MOV   R6,0AH                       ;0007   AE0A                   MOV   R7,0BH                       ;0009   AF0B                   MOV   R0,#0FH                      ;000B   780FQ000D:            

3、 MOV   A,R7                         ;000D   EF                   MOV   C,ACC.2                      ;000E   A2E2                   MOV   A,R4                         ;0010   EC                   JB    ACC.6,Q0015                  ;0011   20E601                   CPL   C                    

4、        ;0014   B3Q0015:             ANL   A,R5                         ;0015   5D                   ANL   A,R6                         ;0016   5E                   ANL   A,R7                         ;0017   5F                   CPL   A                            ;0018   F4                

5、   JNZ   Q001F                        ;0019   7004                   MOV   R4,A                         ;001B   FC                   MOV   R5,A                         ;001C   FD                   MOV   R6,A                         ;001D   FE                   MOV   R7,A                   

6、      ;001E   FFQ001F:             MOV   A,R7                         ;001F   EF                   RRC   A                            ;0020   13                   MOV   R7,A                         ;0021   FF                   MOV   A,R6                         ;0022   EE                  

7、 RRC   A                       &nb2、一个简单的随机数发生函数：rand8reg是得到的随机数，为了更随机，可以把它与定时器相加如果可以把rand8reg保存在非易失性存储器中更好，但是什么时候保存需要认真考虑;==============================================================;  NAME:rand8;  DESCRIPTION:geta8bitrandomNUMBER;  Function:Thisroutinesend