NEC PD75P402 Manuale Utente

The 

µ

PD75402A can incorporate internal pull-up resistors for all port pins except P00 and P10. The 

µ

PD75P402

can incorporate internal pull-up resistors for all port pins except P00, P10, and P50 through P53.

As shown in Table 5-4, internal pull-up resistors can be specified by software or by a mask option (although

specification by mask option is not possible on the 

µ

PD75P402).

The pull-up resistor specification register which specifies internal pull-up resistors for ports 0 through 3 and 6

(POGA) is an 8-bit write-only register. Its format is shown in Fig. 5-7. POGA is set by an 8-bit write instruction. Reading

and bit manipulation is not possible. RESET input clears this register to zero.

Internal pull-up resistor specification for port 3 is valid only for input pins specified as in input mode. The status

of pins specified as in output mode is “without pull-up resistor” irrespective of the POGA setting.

Port (Pin Name)

Internal Pull-Up Resistor Specification Method

Specification Bits

Port 0 (P01 to P03)*1

3-bit unit internal specification by software

POGA.0

Port 1 (P12)*1

Internal specification by software

POGA.1

Port 2 (P20 to P23)

4-bit unit internal specification by software

POGA.2

Port 3 (P30 to P33)

POGA.3

Port 6 (P60 to P63)

POGA.6

Port 5 (P50 to P53)

Bit-wise internal specificationby mask option*2

1. Pull-up resistors cannot be incorporated into the P00 and P10 pins.

2. On the 

µ

PD75P402, pull-up resistors cannot be incorporated into port 5.