di2489l1.txt
;**************************************************************************************************
; Listing 1 - STANDARD INTERRUPT-HANDLING SOFTWARE
;
; "Software avoids interrupt overhead," EDN, March 2, 2000, pg 116
; http://www.ednmag.com/ednmag/reg/2000/030200/designideas.htm#05di2
;***********************************************************************************************

static interrupt (0x1F) void UartIrq ( void ) /* EX7 = vector 0x1f, address 0x7c */
{
	switch ( (uiPortBase + IIR) & 6 ) /* read interrupt identification register */
	{
		case 0:
		/* do something to handle the ID 0 */
			break;
		case 2:
		/* do something to handle the ID 2 */
			break;
		case 4:
		/* do something to handle the ID 4 */
			break;
		case 6:
		/* do something to handle the ID 6 */
			break;
	}			
}