delay.c

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/***********************************************************/
/*							                               */
/*                CPU:AT89c55   20MHZ                      */
/*                Copyright  2004.09  Comelit              */
/*                AUTHOR:  LV_XIAO_LU                      */
/*                                                         */
/***********************************************************/
#include "reg52.h"
/*11.059MHZ 1machine time = 1.085us*/
void Delay_10ms(void);
/*以下函数为在CPU时钟是11.0592MHZ时所用*/
/*void Delay_10ms(void)
{
#pragma asm
  push 0H          //1
  push 1H          //1
  mov r0,#0x0a     //1
/*1ms*/
/*large_loop:
  mov r1 ,#0x73     //1
small_loop:
     nop
	 nop
	 nop
	 nop
	 nop
	 nop
     djnz r1, small_loop   //2
/*1ms over*/
/*	 djnz r0,large_loop    //2
  pop 1H                   //1
  pop 0H                   //1
#pragma endasm

}*/
/*以下函数为CPU时钟是20MHZ时所用*/
/* 1个时钟周期为0.6us*/
void Delay_10ms(void)
{
#pragma asm
  push 0H          //1
  push 1H          //1
  mov r0,#0x0a     //1
/*1ms*/
large_loop:
  mov r1 ,#0xd0     //1
     nop
	 nop
small_loop:
     nop
	 nop
	 nop
	 nop
	 nop
	 nop
     djnz r1, small_loop   //2
/*1ms over*/
	 djnz r0,large_loop    //2
  pop 1H                   //1
  pop 0H                   //1
#pragma endasm

}