
S1C88348/317/316/308 TECHNICAL HARDWARE
EPSON
I-133
5 PERIPHERAL CIRCUITS AND THEIR OPERATION (Sound Generator)
5.13.6 Control of sound generator
Table 5.13.6.1 shows the sound generator control bits.
Table 5.13.6.1 Sound generator control bits
BZON: 00FF44HD0
Controls the BZ signal output.
When "1" is written: BZ signal output
When "0" is written: LOW level (DC) output
Reading:
Valid
BZON is the output control register for BZ signal.
When "1" is set, the BZ signal is output from the
output port terminal R50 and when "0" is set, LOW
(VSS) level is output. At this time, "0" must always
be set for the data register R50D.
At initial reset, BZON is set to "0" (LOW level
output).
BZFQ0–BZFQ2: 00FF45HD0–D2
Selects the BZ signal frequency.
Table 5.13.6.2 Buzzer frequency settings
BZFQ2
Buzzer frequency (Hz)
0
1
4096.0
3276.8
2730.7
2340.6
2048.0
1638.4
1365.3
1170.3
BZFQ1
0
1
0
1
BZFQ0
0
1
0
1
0
1
0
1
The buzzer frequency can be selected from among
the above 8 types that have divided the OSC1 clock.
At initial reset, this register is set at "0" (4096.0 Hz).
Address Bit
Name
SR R/W
Function
Comment
10
00FF44 D7
D6
D5
D4
D3
D2
D1
D0
–
BZSTP
BZSHT
SHTPW
ENRTM
ENRST
ENON
BZON
–
One-shot buzzer forcibly stop
One-shot buzzer trigger/status
One-shot buzzer duration width selection
Envelope attenuation time
Envelope reset
Envelope On/Off control
Buzzer output control
Constantry "0" when
being read
"0" when being read
*1
–
0
–
0
W
R/W
W
R/W
–
Forcibly stop
Busy
Trigger
125 msec
1 sec
Reset
On
–
No operation
Ready
No operation
31.25 msec
0.5 sec
No operation
Off
00FF45 D7
D6
D5
D4
D3
D2
D1
D0
–
DUTY2
DUTY1
DUTY0
–
BZFQ2
BZFQ1
BZFQ0
–
Buzzer signal duty ratio selection
–
Buzzer frequency selection
"0" when being read
–
0
–
0
R/W
–
0
1
R
W
0
1
0
1
0
1
0
1
0
1
0
1
8/16
7/16
6/16
5/16
4/16
3/16
2/16
1/16
4096.0
2048.0
8/20
7/20
6/20
5/20
4/20
3/20
2/20
1/20
3276.8
1638.4
12/24
11/24
10/24
9/24
8/24
7/24
6/24
5/24
2730.7
1365.3
12/28
11/28
10/28
9/28
8/28
7/28
6/28
5/28
2340.6
1170.3
210
Buzzer frequency (Hz)
DUTY2–1
BZFQ2
0
1
BZFQ1
0
1
0
1
BZFQ0
0
1
0
1
0
1
0
1
Frequency (Hz)
4096.0
3276.8
2730.7
2340.6
2048.0
1638.4
1365.3
1170.3
*1 Reset to "0" during one-shot output.