15 SOunD GeneRaTOR
15-6
Seiko epson Corporation
S1C63003/004/008/016 TeChniCal Manual
(Rev. 1.1)
BZSTP: One-shot buzzer stop (FF45h•D2)
Stops the one-shot buzzer output.
When "1" is written: Stop
When "0" is written: No operation
Reading: Always "0"
Writing "1" to BZSTP permits the one-shot buzzer output to be turned off prior to the elapsing of the time set by
SHTPW. Writing "0" is invalid and writing "1" is also invalid except during one-shot output. This bit is dedicated
for writing, and is always "0" for reading.
BZFQ[2:0]: Buzzer frequency select register (FF46h•D[2:0])
Selects the buzzer signal frequency.
7.2 Buzzer signal frequency setting
Table 15.
BZFQ[2:0]
Buzzer frequency (Hz)
0
4096.0
1
3276.8
2
2730.7
3
2340.6
4
2048.0
5
1638.4
6
1365.3
7
1170.3
Select the buzzer frequency from among the above 8 types that have divided the oscillation clock. At initial reset,
this register is set to "0."
BDTY[2:0]: Duty level select register (FF47h•D[2:0])
Selects the duty ratio of the buzzer signal as shown in Table 15.7.3.
7.3 Duty ratio setting
Table 15.
Level
BDTY[2:0]
Duty ratio by buzzer frequency (Hz)
4096.0
3276.8
2730.7
2340.6
2048.0
1638.4
1365.3
1170.3
Level 1 (Max.)
0
8/16
8/20
12/24
12/28
Level 2
1
7/16
7/20
11/24
11/28
Level 3
2
6/16
6/20
10/24
10/28
Level 4
3
5/16
5/20
9/24
9/28
Level 5
4
4/16
4/20
8/24
8/28
Level 6
5
3/16
3/20
7/24
7/28
Level 7
6
2/16
2/20
6/24
6/28
Level 8 (Min.)
7
1/16
1/20
5/24
5/28
The sound level of this buzzer can be set by selecting this duty ratio. However, when the envelope has been set to
on (ENON = "1"), this setting becomes invalid. At initial reset, this register is set to "0."
Precautions
15.8
• Since it generates a 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.
• The one-shot output is only valid when the normal buzzer output is off (BZE = "0") and will be invalid when the
normal buzzer output is on (BZE = "1").