NEC PD75402A Manuale Utente

The different types of digital input/output ports are shown in Table 5-1, and the configuration of each port is shown

in Figs. 5-2, 5-3, 5-4 and 5-5.

Port

(Symbol)

 Function

Can always be read or tested
regardless of dual-function pin
operating mode.

Can be set to input or output
mode bit by bit.

Can be set to input or output
mode as a 4-bit unit.

Can be set to input or output
mode as a 4-bit unit.

 Operation/Characteristics

Remarks

PORT0

4-bit input

PORT1

PORT3*

4-bit input/output

PORT2
PORT6*

PORT5*

4-bit input/ output
(N-ch open-drain,
up to 10 V)

Pins also function as SO/SB0, SI,
SCK, INT0, INT2. (See chapter 1.)

Port 2 pins also function as PCL.

Internal pull-up resistor can be
specified bit by bit by mask
option.  (

µ

PD75402A only.)

LED direct drive capability

On the 

µ

PD75402A, a pull-up resistor can be incorporated on chip for all port pins except pins P00, P10. On the

µ

PD75P402, a pull-up resistor can be incorporated on chip for all port pins except pins P00, P10, and P50 through

P53 (see section 5.5).

P10 has a dual function as the external vectored interrupt input pin, and has an on-chip circuit for noise elimination

by the sampling clock (see section 6.2 for details).

Upon RESET input the output latches of ports 2, 3, 5 and 6 are cleared, the output buffer is turned off, and input

mode is set.