22.c

C51实用程序（45个） I/O、定时器、中断、看门狗、计数器、软件AD、VB串口、93c06驱动、24c02系列驱动、7219、20045、软件陷阱、串口中断、码值转换、AVR通讯、IIC、D

#ifdef ASM
      unsigned long shiftR1(register unsigned long);
#else    
         extern unsigned long shiftR1(register unsigned long);
#endif
//end of asm.h

//<asm.c>
#define ASM
#include <asm.h>
#include <reg52.h>
#pragma OT(4,speed)
unsigned long  shiftR1(register unsigned long  x)
{
    #pragma asm
    clr c
    mov a,r4
    rrc a
    mov r4,a

    mov a,r5
    rrc a
    mov r5,a

    mov a,r6
    rrc a
    mov r6,a

    mov a,r7
    rrc a
    mov r7,a
    
    #pragma endasm
    return(x);
}