P30 To P37 (Port 3) - NEC PD78056F User Manual

(d) BUSY
Serial interface automatic transmit/receive busy input pins
(e) STB
Serial interface automatic transmit/receive strobe output pins
Caution When this port is used as a serial interface pin, the I/O and output latches must be set
according to the function the user requires. For the setting, refer to Figure 16-4 "Serial
Operating Mode Register 0 Format" and Figure 18-3 "Serial Operating Mode Register
1 Format."

3.2.4 P30 to P37 (Port 3)

These are 8-bit input/output ports. Beside serving as input/output ports, they function as timer input/output, clock
output and buzzer output.
The following operating modes can be specified bit-wise.
(1) Port mode
These ports function as 8-bit input/output ports. They can be specified bit-wise as input or output ports with
port mode register 3 (PM3). When they are used as input ports, on-chip pull-up resistors can be used by
defining the pull-up resistor option register L (PUOL).
(2) Control mode
These ports function as timer input/output, clock output, and buzzer output.
(a) TI1 and TI2
Pin for external count clock input to the 8-bit timer/event counter.
(b) TO0 to TO2
Timer output pins.
(c) PCL
Clock output pin.
(d) BUZ
Buzzer output pin.
CHAPTER 3 PIN FUNCTION ( PD78058F SUBSERIES)
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