15 SOunD GeneRaTOR
S1C63003/004/008/016 TeChniCal Manual
Seiko epson Corporation
15-1
(Rev. 1.1)
Sound Generator
15
Configuration of Sound Generator
15.1
The S1C63003/004/008/016 has a built-in sound generator for generating a buzzer signal. Hence, the generated
buzzer signal can be output from the BZ terminal. Aside permitting the respective setting of the buzzer signal fre-
quency 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 15.1.1 shows the configuration of the sound
generator.
f
OSC1
f
OSC1
/128
SGCKE
Clock
manager
BZ (P12) terminal
Programmable
dividing circuit
One-shot buzzer
control circuit
Duty ratio
control circuit
BZFQ[2:0]
BDTY[2:0]
Buzzer output
control circuit
Envelope
addition circuit
ENON
BZE
ENRTM
ENRST
BZSTP
BZSHT
SHTPW
1.1 Configuration of sound generator
Figure 15.
Note: If the BZ terminal is used to drive an external component that consumes a large amount of current
such as a bipolar transistor, design the pattern of traces on the printed circuit board so that the
operation of the external component does not affect the IC power supply. Refer to "Precautions on
Mounting" in the Appendix for more information.
Controlling Operating Clock
15.2
To generate the buzzer signal, the clock for the sound generator must be supplied from the clock manager by writing
"1" to the SGCKE register in advance.
2.1 Controlling sound generator clock
Table 15.
SGCKE
Sound generator clock
1
Programmable dividing circuit input clock: f
OSC1
(32 kHz)
One-shot buzzer control circuit input clock: f
OSC1
/ 128 (256 Hz)
0
Off
If it is not necessary to run the sound generator, stop the clock supply by setting SGCKE to "0" to reduce current
consumption.
Buzzer Output Control
15.3
The BZ signal generated by the sound generator is output from the BZ (P12) terminal by setting "1" for the buzzer output
enable register BZE. The I/O control register IOC12 and data register P12 settings are ineffective while the BZ signal is
being output. When BZE is set to "0," the P12 port is configured as a general-purpose DC input/output port.
BZE register
BZ output (P12 terminal)
"1"
"0"
"0"
3.1 Buzzer signal output timing chart
Figure 15.
Note: Since it generates the buzzer signal that is out of synchronization with the BZE register, hazards
may at times be produced when the signal goes on/off due to the setting of the BZE register.