Rainbow Electronics W79E8213R - Manual (Page 78)

Preliminary W79E8213/W79E8213R Data Sheet
Publication Release Date: July 11, 2008
- 78 - Revision A2
For supporting active low buzzer, this buzzer output is implemented with an off-state of high. The
following pseudo code shows the operating procedure when working with active high and low buzzer;
(Assume PRHI=1):
1) During power on, P1.0/BUZ will be high;
<For active high buzzer>
Clear SFR P1.0
; user has to take care to output this pin low
; at the top of s/w code to avoid initial beep sound.
<For active low buzzer>
No action needed.
2) To turn-on buzzer;
<For active high buzzer>
Set BUZE bit
Set SFR P1.0 bit
; to push out the buzout.
<For active low buzzer>
Set BUZE bit
3) To turn-off buzzer;
<For active high buzzer>
Clear SFR P1.0
; user has to take care to output this pin low.
Clear BUZE bit
<For active low buzzer>
Set BUZE bit