Control Of Sound Generator - Epson 0C88832 Technical Manual

5 PERIPHERAL CIRCUITS AND THEIR OPERATION (Sound Generator)

5.12.6 Control of sound generator

Table 5.12.6.1 shows the sound generator control bits.
Address Bit Name
00FF44 D7 –
–
D6 BZSTP One-shot buzzer forcibly stop
D5 BZSHT
One-shot buzzer trigger/status
D4 SHTPW
One-shot buzzer duration width selection
D3 ENRTM Envelope attenuation time
D2 ENRST
Envelope reset
D1 ENON Envelope On/Off control
D0 BZON
Buzzer output control
00FF45 D7 – –
D6 DUTY2
Buzzer signal duty ratio selection
D5 DUTY1
D4 DUTY0
D3 – –
D2 BZFQ2
Buzzer frequency selection
D1 BZFQ1
D0 BZFQ0
*1 Reset to "0" during one-shot output.
BZON: 00FF44H•D0
Controls the buzzer (BZ and BZ) signal output.
When "1" is written: Buzzer signal output ON
When "0" is written: Buzzer signal output OFF
Reading:
BZON is the output control register for buzzer
signal. When "1" is set to the register, the BZ (BZ)
signal is output from the output port terminal R50
(R51). When "0" is set, the R50 goes LOW (V
the R51 goes HIGH (V
DD
To output the BZ signal, "0" must always be set for
the data register R50D. The data register R51D does
not affect the BZ output.
At initial reset, BZON is set to "0" (output OFF).
The BZ signal can be output from R51 only when
the function is selected by mask option.
106
Table 5.12.6.1 Sound generator control bits
Function
DUTY2–1 Buzzer frequency (Hz)
4096.0 3276.8 2730.7
2 1 0
2048.0 1638.4 1365.3
0 0 0 8/16 8/20 12/24
0 0 1 7/16 7/20 11/24
0 1 0 6/16 6/20 10/24
0 1 1 5/16 5/20 9/24
1 0 0 4/16 4/20 8/24
1 0 1 3/16 3/20 7/24
1 1 0 2/16 2/20 6/24
1 1 1 1/16 1/20 5/24
BZFQ2 BZFQ1 BZFQ0 Frequency (Hz)
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
Valid
) and
SS
).
1
–
Forcibly stop No operation
R
Busy
W
Trigger No operation
125 msec
1 sec
Reset No operation
On
On
–
2340.6
1170.3
12/28
11/28
10/28
9/28
8/28
7/28
6/28
5/28
–
4096.0
3276.8
2730.7
2340.6
2048.0
1638.4
1365.3
1170.3
BZFQ0–BZFQ2: 00FF45H•D0–D2
Selects the buzzer signal frequency.
Table 5.12.6.2 Buzzer frequency settings
BZFQ2 BZFQ1
0 0
0 0
0 1
0 1
1 0
1 0
1 1
1 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).
EPSON
0 SR R/W Comment
–
– Constantry "0" when
– W
being read
0 R/W
Ready
0 R/W
31.25 msec
0 R/W
0.5 sec
– W
"0" when being read
0 R/W
Off *1
0 R/W
Off
–
– "0" when being read
0 R/W
0 R/W
0 R/W
–
– "0" when being read
0 R/W
0 R/W
0 R/W
BZFQ0 Buzzer frequency (Hz)
0 4096.0
1 3276.8
0 2730.7
1 2340.6
0 2048.0
1 1638.4
0 1365.3
1 1170.3
E0C88832/88862 TECHNICAL MANUAL