Overview Of Buzzer Output - Fujitsu F2MC-8L MB89620 Series Hardware Manual

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11.

Overview of Buzzer Output

The buzzer output can select from three different output frequencies (square waves)
and can be used for applications such as sounding a buzzer to confirm key input.
n Buzzer Output Function
The buzzer output function outputs a signal (square wave) suitable for applications such as
sounding a buzzer to confirm an operation.
The buzzer register (BZCR) enables buzzer output and selects the frequency.
Setting any value other than "00
frequency from the BZ pin.
Check: As the buzzer output clock is taken directly from the timebase timer output, clearing the timebase
Table 11.1 lists the three output frequencies (square waves) that can be selected for the buzzer
output function.
Table 11.1 Output Frequency
F : Source oscillation
C
The value enclosed in parentheses ( ) are for a 10 MHz source oscillation.
Note: Calculation example for output frequency
For a 10 MHz source oscillation and if the buzzer register (BZCR) selects a timebase timer cycle of
F
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CHAPTER 11 BUZZER OUTPUT
timer has an effect on the clock.
Timebase timer cycle
13
2 /F
C
2 12 /F
C
2 11 /F
C
11
/2 (BZ1 = "1", BZ0 = "1"), the output frequency of the BZ pin is calculated as follows:
C
Output frequency = F
=10 MHz/2048
" to the BZCR register outputs a square wave of the specified
B
Square wave output (Hz)
13
F /2 (1.221 kHz)
C
F /2 12 (2.441 kHz)
C
F /2 11 (4.883 kHz)
C
11
/2
C
4.883 kHz
MB89620 series