Z51F3220FNX Datasheet, PDF (173/312 Pages) Zilog, Inc. – Z8051 Series 8-Bit Microcontrollers

Z51F3220
Product Specification
11.9 Buzzer Driver
11.9.1 Overview
The Buzzer consists of 8 bit counter, buzzer data register (BUZDR), and buzzer control register (BUZCR). The
Square Wave (61.035Hz~125.0 kHz @8MHz) is outputted through P13/SEG17/AN10/EC1/BUZO pin. The
buzzer data register (BUZDR) controls the bsuzzer frequency (look at the following expression). In buzzer control
register (BUZCR), BUCK[1:0] selects source clock divided by prescaler.
f_BUZ (Hz)

Oscillator Frequency
2  Prescaler Ratio  (BUZDR
 1)
Table 11-15 Buzzer Frequency at 8 MHz
BUZDR[7:0]
0000_0000
0000_0001
…
1111_1101
1111_1110
1111_1111
BUZCR[2:1]=00
125kHz
62.5kHz
…
492.126Hz
490.196Hz
488.281Hz
Buzzer Frequency (kHz)
BUZCR[2:1]=01
BUZCR[2:1]=10
62.5kHz
31.25kHz
31.25kHz
15.625kHz
…
…
246.063Hz
123.031Hz
245.098Hz
122.549Hz
244.141Hz
122.07Hz
BUZCR[2:1]=11
15.625kHz
7.812kHz
…
61.515Hz
61.274Hz
61.035Hz
11.9.2 Block Diagram
BUZEN
fx/32
fx/64
fx
Pre
scaler ^fx/128
MUX
fx/256
8-bit Up-Counter
Counter
Clear
F/F
BUZO
2
Comparator
BUCK[1:0]
BUZDR
Figure 11.48 Buzzer Driver Block Diagram
PS029902-0212
PRELIMINARY
170