mc68hc05l25 Freescale Semiconductor, Inc, mc68hc05l25 Datasheet - Page 87

• Manufacturer Part Number: mc68hc05l25
• Description: M68hc05 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

9.2.6 Buzzer Tone Generator
The PA3/KWI3/BZ pin functions as a general-purpose I/O port after reset. The BZPE bit must be set in
order to use this port as buzzer tone output. The BZ outputs idle state is set by the BPOL bit when BZON
is cleared. The BZCLK signal selected by the BCLK bit is output on the pin when BZON is set. The BZ
output pin is open drain.
Freescale Semiconductor
TBCR1
TBCLK
0
0
1
1
*The BZ output pin is open drain. The logic 1 shown for the BZ pin is actually a hi-Z state unless it is a pullup.
TBCR3BCLK
0
1
0
1
PA3/BZ*
BZCLK
BZON
BZPE
BPOL
f
XOSC
Approximately
Approximately
PC2 I/O PORT
f
OSC
4096 Hz
2048 Hz
1953 Hz
977 Hz
= 32.768 kHz
Figure 9-4. Buzzer Tone Output Control
= 2 MHz
MC68HC05L25 Data Sheet, Rev. 3.1
Table 9-5. Buzzer Frequency
IDLE
f
XOSC
f
OSC
Approximately
Approximately
Buzzer Frequency on BZ Pin (BZCLK)
4096 Hz
2048 Hz
3516 Hz
1758 Hz
= 32.768 kHz
= 3.6 MHz
CLOCK OUT
BZ PORT
f
XOS
Approximately
Approximately
f
OSC
c = 32.768 kHz
4096 Hz
2048 Hz
3906 Hz
1953 Hz
IDLE
= 4 MHz
PC2 I/O PORT
Time Base Submodules
f
OSC
f
XOSC
= 4.194304 MHz
4096 Hz
2048 Hz
4096 Hz
2048 Hz
= 32.768 kHz
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