
38
EPSON
S1C63808 TECHNICAL MANUAL
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Output Ports)
BZE: Buzzer output control register (FF6CHD0)
Controls the buzzer signal output.
When "1" is written: Buzzer output On
When "0" is written: Buzzer output Off
Reading: Valid
By writing "1" to the BZE register when the R01 register has been set to "1" and the R01HIZ register has
been set to "0", the BZ signal is output from the R01 terminal. When "0" is written, the R01 terminal goes
low (VSS).
At initial reset, this register is set to "0".
BZSHT: One-shot buzzer trigger/status (FF6DHD1)
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 R01 terminal. To output the buzzer signal, the R01 register must be set to "1" and the R01HIZ
register must be set to "0".
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: BUSY
When "0" is read: READY
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 bit is set to "0".
4.5.6 Programming notes
(1) When using the output port (R01, R02, R03) as the special output port (BZ, TOUT, FOUT), fix the data
register (R01, R02, R03) at "1" and the high impedance control register (R01HIZ, R02HIZ, R03HIZ) at
"0" (data output).
Be aware that the output terminal is fixed at a low (VSS) level the same as the DC output if "0" is
written to the R01, R02 and R03 registers when the special output has been selected.
Be aware that the output terminal shifts into high impedance status when "1" is written to the high
impedance control register (R01HIZ, R02HIZ, R03HIZ).
(2) A hazard may occur when the BZ, FOUT or TOUT signal is turned on and off.
(3) When fOSC3 is selected for the FOUT signal frequency, it is necessary to control the OSC3 oscillation
circuit before output.
Refer to Section 4.3, "Oscillation Circuit", for the control and notes.