delay.asm

来自「DSP5000实验箱上完整的实验程序,很有参考价值」· 汇编 代码 · 共 34 行

;延时子程序  delay.asm
;===============================================
		.global  ms_delay ,us_delay,t_delay1,t_delay2
ms_delay: 
	stm 	#1444h,ar4		;1ms=4(cycles)x5000x0.05us   1388h=5000d(f=10MHz)
ms_loop:	
    banz 	ms_loop,*ar4-
	banz 	ms_delay,*ar3-
	ret
;===============================================	
us_delay: 
	;stm  #184h,ar4			;1us=4(cycles)x5x0.05us   (5h=5d)    (f=10MHz)
    stm  #4h,ar4
us_loop:					
	banz 	us_loop,*ar4-   ;1 个指令周期 = 0.05uS=1*1/20us(when f=20MHz=10MHzx2)
	banz 	us_delay,*ar3-  ;banz	when TRUE  4 cycles
	nop
	ret						;            FALSE 2 cycles
							;stm	2 cycles
							;0f9h=>249d
							;270fh=>9999d 
;===============================================
t_delay1:
		nop
		nop
		nop
		nop
		nop			
		ret
t_delay2:
		nop
		nop
        ret
;===============================================