delay.asm

AVR ATMega library for using MMC /SD cart.

/* ***********************************************************************
**
**  Copyright (C) 2002  Jesper Hansen <[e-mail]> and 
**			Romuald Bialy (MIS) <[e-mail]>.
**
**
**  Yampp-7/USB - low level support library
**
**
*************************************************************************
**
**   This file is part of the yampp system.
**
**  This program is free software; you can redistribute it and/or
**  modify it under the terms of the GNU General Public License
**  as published by the Free Software Foundation; either version 2
**  of the License, or (at your option) any later version.
**
**  This program is distributed in the hope that it will be useful,
**  but WITHOUT ANY WARRANTY; without even the implied warranty of
**  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
**  GNU General Public License for more details.
**
**  You should have received a copy of the GNU General Public License
**  along with this program; if not, write to the Free Software Foundation, 
**  Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
**
*************************************************************************
**
**  Revision History
**
**  when         what  who	why
**
**  2002-09-22   1.0   MIS      initial public release
**
*********************************************************************** */

#include "Constants.h"

;********************************************************************
;*
;*  Delay stuff 
;*
;********************************************************************

;
;void delay10(void) 

#define LOOPS		(((F_CPU / 100000) - 8) / 3)

.global delay10
delay10:
		ldi	r24,LOOPS	; 1 cycle
d10l: 		dec	r24		; 1 cycle
 		brne	d10l		; 2 (1) cycle
 		ret			; + 8 cycles for call and ret


;void delay100(void) 
.global delay100
delay100:
 		ldi 	r25,10
d100l: 		rcall 	delay10
		dec	r25
		brne	d100l
		ret


;			r25/r24
;void delayms(u16 ms)
.global delayms
delayms:
		push 	r24
		push	r25

 		ldi 	r25,100
del1m:		rcall 	delay10
		dec	r25
		brne	del1m

 		wdr
		pop	r25
		pop	r24
 
 		sbiw	r24,1
 		brne	delayms
 		
		ret