HT45F43 datasheet(125/152 Pages) HOLTEK

125 / 152 page

If the options have selected that only the PA6 pin is to function as a BZ buzzer pin, then the PA7 pin

can be used as a normal I/O pin. For the PA6 pin to function as a BZ buzzer pin, PA6 must be setup as

an output by setting bit PAC6 of the PAC port control register to zero. The PA6 data bit in the PA data

way the PA6 bit can be used as an on/off control for the BZ buzzer pin PA6. If the PAC6 bit of the

PAC port control register is set high, then pin PA6 can still be used as an input even though the option

has configured it as a BZ buzzer output.

Note that no matter what BPCTL option is chosen for the buzzer, if the port control register has setup

the pin to function as an input, then this will override the BPCTL option selection and force the pin to

always behave as an input pin. This arrangement enables the pin to be used as both a buzzer pin and as

an input pin, so regardless of the BPCTL option chosen; the actual function of the pin can be changed

dynamically by the application program by programming the appropriate port control register bit.

HT45F23/HT45F43

8-Bit Flash MCU with Op Amps & Comparators

Rev. 1.20

125

September 15, 2011

I n t e r n a l C l o c k S o u r c e , f T B

P A 6 D a t a

B Z O u t p u t a t P A 6

B Z O u t p u t a t P A 7

P A 7 D a t a

Buzzer Output Pin Control

Note:

The above drawing shows the situation where both pins PA6 and PA7 are selected by BPCTL option to be BZ

and BZ buzzer pin outputs. The Port Control Register of both pins must have already been setup as output.

The data setup on pin PA7 has no effect on the buzzer outputs.

HT45F43 Datasheet(PDF) 125 Page - Holtek Semiconductor Inc