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(3) Special output control
FOUT0–FOUT3: FOUT frequency select register (FF10H)
Selects the frequency of the FOUT signal and controls the FOUT output.
f
: OSC1 oscillation frequency. ( ) indicates the clock frequency when fOSC1 = 32 kHz.
OSC1
f
: OSC3 oscillation frequency
OSC3
Selecting an FOUT frequency (writing 1–15 to this register) outputs the FOUT signal from the P23 terminal.
Set FOUT0–FOUT3 to "0" to use P23 as a general-purpose DC input/output port.
At initial reset, these registers are set to "0".
BZE: Buzzer output control register (FF44H•D0)
Controls the buzzer signal output.
When "1" is written: Buzzer output On
When "0" is written: Buzzer output Off
Reading: Valid
When "1" is written to BZE, the BZ signal is output from the P03 terminal. When "0" is written, P03 is used
as a general-purpose DC input/output port.
At initial reset, this register is set to "0".
BZSHT: One-shot buzzer trigger/status (FF45H•D1)
Controls the one-shot buzzer output.
• When writing
When "1" is written: Trigger
When "0" is written: No operation
Writing "1" into BZSHT causes the one-short output circuit to operate and a buzzer signal to be output from
the P03 terminal. This output is automatically turned off after the time set by SHTPW has elapsed. 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"). When a re-trigger is assigned during a one-shot output, the one-
shot output time set with SHTPW is measured again from that point (time extension).
• When reading
When "1" is read:
When "0" is read:
During reading BZSHT shows the operation status of the one-shot output circuit. During one-shot output,
BZSHT becomes "1" and the output goes off, it shifts to "0".
At initial reset, this register is set to "0".
Table 4.5.8.3 FOUT clock frequency
FOUT3
FOUT2
FOUT1
1
1
1
1
1
1
1
1
0
1
1
0
1
0
1
1
0
1
1
0
0
1
0
0
0
1
1
0
1
1
0
1
0
0
1
0
0
0
1
0
0
1
0
0
0
0
0
0
BUSY
READY
FOUT0
FOUT frequency
1
f
OSC3
0
f
/ 2
OSC3
1
f
/ 4
OSC3
0
f
/ 8
OSC3
1
f
/ 16
OSC3
0
f
/ 32
OSC3
1
f
/ 64
OSC3
0
f
/ 256
OSC3
1
f
(32 kHz)
OSC1
0
f
/ 2
(16 kHz)
OSC1
1
f
/ 4
(8 kHz)
OSC1
0
f
/ 16 (2 kHz)
OSC1
1
f
/ 32 (1 kHz)
OSC1
0
f
/ 64 (512 Hz)
OSC1
1
f
/ 256 (128 Hz)
OSC1
0
Off
SIC63616-(Rev. 1.0) NO. P60
3240-0412
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