ms744l3.txt
;************************************************************************************************
; LISTING 3 - SUBROUTINE FOR PSEUDO TIMER/COUNTER DEBOUNCING CODE
;
; "Interfacing switches and relays to the real world in real time," EDN, June 7, 2001, pg 135
;
; http://www.ednmag.com/ednmag/reg/2001/060701/13ms744.htm
;************************************************************************************************

Debouncing Time/Counter Subroutine

1 DB_Check_Port: Read Port Data
2 Store Port_Data in Port1
3 Compare Port1 with Port_P, (EX-OR Port1 with Port_P)
4 Test for Bit Changes,  (No) Return from Check_Port subroutine, (Yes) continue
5 Store 50ms_Count in Counter
6 DB_TMR:	Decrement Counter by 1
7 Test Counter = 0, (No) goto DB_TMR, (Yes) continue
8 Store Port_Data in Port_P
9 {do some thing with the new port data}
10 Return from Check_Port subroutine with new Port_P data for main program