Sound Generator; Configuration Of Sound Generator; Buzzer Output Circuit - Epson S1C63558 Technical Manual

CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Sound Generator)

4.12 Sound Generator

4.12.1 Configuration of sound generator

The S1C63558 has a built-in sound generator for generating buzzer signals. Hence, generated buzzer
signals can be output from the R00 (XBZ) and R01 (BZ) terminals. Aside permitting the respective setting
of the buzzer signal frequency and sound level to 8 stages, it permits the adding of a digital envelope by
means of duty ratio control. It also has a one-shot output function for outputting key operated sounds.
Figure 4.12.1.1 shows the configuration of the sound generator.
BZFQ0–BZFQ2
Programmable
f
OSC1
dividing circuit
One-shot buzzer
256 Hz
control circuit
BZSHT
BZSTP
SHTPW

4.12.2 Buzzer output circuit

The S1C63558 uses the R01 (BZ) and R00 (XBZ) terminals for outputting buzzer signals. To drive a
piezoelectric buzzer with one terminal, use the BZ signal output from the R01 (BZ) terminal. The piezo-
electric buzzer should be driven via a bipolar transistor. Since the R01 (BZ) terminal goes High level
when the buzzer signal is stopped, use a PNP transistor as shown in Figure 4.12.2.1.
The S1C63558 allows direct driving of a piezoelectric buzzer using both the R01 (BZ) and R00 (XBZ)
terminals. In this case, a piezoelectric buzzer should be connected to these terminals via protection
resistors (100 ) as shown in Figure 4.12.2.2.
Fig. 4.12.2.2 Direct driving a piezoelectric buzzer using the R01 (BZ) and R00 (XBZ) terminals
100
BDTY0–BDTY2
Duty ratio
control circuit
Fig. 4.12.1.1 Configuration of sound generator
V
R01 (BZ)
V
Fig. 4.12.2.1 Buzzer output circuit using the R01 (BZ) terminal
R01 (BZ)
R00 (XBZ)
ENON
Envelope
addition circuit
Buzzer output
control circuit
BZE
V
DD DD
SS
EPSON
ENRST
ENRTM
R00 (XBZ)
R00, R01
output circuit
R01 (BZ)
BZOUT XBZOUT
S1C63558 TECHNICAL MANUAL