pll42dly.asm

ADUC842 C程序集,包括ADC,DAC,PLL,PWM,WDT等程序．

;File: pll42dly.a51
;Author: Eckart Hartmann Date:05/10/2003
;Development progress: Pll842.df
;
;PllDly==========Software delay
;C Function prototype: char PllDly(uint uDlyMs);
;Description of Function: Causes software delay of uDlyMs milliseconds.
;User interface: Put delay in parameter1. Call PllDly.
;		Returns with 1 (always).
;Robustness:	Due to unavoidable rounding the delay times have typical 
;		errors of up to 3%.
;		An offset of about 15us*2^CD (as much as 2ms at CD=7)
;		becomes dominant for large CD and small delays.
;		Delay will be increased if normal interrupts occur during delay.
;		Delay can be decreased if fast interrupts occur during delay.
;		Delay will be incorrect if CD is changed by an interrupt.
;		Delay will be incorrect inside an interrupt unless FINT=0 or CD=0.
;Side effects: Overwrites a, p and ip2l.
;

NAME	PLLDLY
$NOMOD51
 $IC(..kei842.inc) ; Parameter passing registers for Keil .
 $IC(..kei842.dat) ; SFR definition for Keil .
;
public _PllDly

?PR?_PllDly?PLLDLY	SEGMENT CODE
	RSEG	?PR?_PllDly?PLLDLY
	
_PllDly:
	mov	a,iP1l		;Start on low byte.
	jnz	PlDLr7
PlDCh6:	mov	a,iP1h
	jz	PlDR		;High byte with low byte full scale.
	dec	iP1h
PlDLr7:	mov	a,PLLCON
	anl	a,#7		;a = 2^(7-CD);
	inc	a
	inc	a
	movc	a,@a+pc		;//Use CD in reverse lookup table.
	sjmp	PlDCd
	db	128
	db	64
	db	32
	db	16
	db	8
	db	4
	db	2
	db	1
PlDCd:	mov	iP2li,a		;a
LpC5:	mov	iP2hi,#42	; * 44
	djnz	iP2hi,$		; * 3 cycles
	djnz	iP2li,LpC5
	djnz	iP1l,PlDCd
	sjmp	PlDCh6
PlDR:	mov	cP1l,#1		;return(1);	// Always.
	ret
;
;Function End==========================================================Function End
end

[Session]
FileCount=2
Active=1
Filespec1=PLL42DLY.A51
Pos1=0,1,-1,-1,-1,-1,160,295,832,1045
Loc1=27,0,9,85,0
Filespec2=PLL842.C
Pos2=0,1,-1,-1,-1,-1,3,6,675,756
Loc2=0,0,0,0,0