di2569.txt
;**************************************************************************************************
; LISTING 1 - FUNCTION-ACCELERATION CODE FOR C16x MICROCONTROLLERS
; 
; "Speed C functions for C16x Microcontrollers," EDN, Aug 3, 2000, pg 130
;
; http://www.ednmag.com/ednmag/reg/2000/08032000/designideas.htm#16di6
;***************************************************************************************************

void far * fast_memset (  void far *pvDest, UCHAR ucVal, UINT uiSize )
{
UINT uiVal;
UINT far *p;
	if ( uiSize )	/* ignore function call if count is 0 */
	{
		p = pvDest;		/* keep a copy of the pointer */
		uiVal = ((UINT) ucVal << 8) + ucVal;	/* create a word to fill the memory */ 
		if ( _pof ( p ) & 1 )	/* if the start address is odd */
		{
			*(UCHAR far*)p = ucVal;		/* write a byte to the start address */
			p = (UINT far*) ((UCHAR far*) p + 1);		/* move pointer to next even address */
			--uiSize;				/* count one byte written*/ 
		}
		USR0 = uiSize & 1;		/* USR0 = 1 if remaining count is odd */
		uiSize >>=1;				/* convert remaining byte count to word count */
		while ( uiSize )			/* write to all words */
		{
			*p = uiVal; 				/* write a word */
			p += 1;		 					/* point to the next word */
			--uiSize;						/* decrement the word counter */
		}
		if ( USR0 )		 				/* if one byte is left*/
		{
			*(UCHAR far*)p = ucVal;				/* write to the last byte */
		}
	}
	return ( pvDest );			/* return the pointer to start of memory area	*/
}