NEC PD75P402, PD75402A PIN Functions Normal Operating Mode, Port 0’s, 1’s Dual-Function Pins

CHAPTER 2. PIN FUNCTIONS

2.2NORMAL OPERATING MODE

2.2.1P00 to P03 (Port 0) ..... SCK, SO/SB0, SI Dual-Function Input P10, P12 (Port 1) ..... INT0, INT2 Dual-Function Input

P00 to P03 are the 4-bit input port: Port 0’s input pins. P10 and P12 are the 2-bit input port: Port 1’s input pins. Ports 0 and 1 also have the functions of the various control signal pins shown in Table 2-1 in addition to the functions as input ports. The status of each of Ports 0 and 1 is always inputtable irrespective of the dual-function

pin operation.

Both Ports 0 and 1 have Schmitt-triggered input to prevent malfunction by noise. P10 is built in with the noise eliminator by the sampling clock and P12 is built in with the noise eliminator by analog delay.

Ports 0 and 1 allow to designate to build in the pull-up resistor respectively in 3-bit units (P01 to P03) and bit- wise (P12 only). Such designation is made using the pull-up resistor designation register (POGA). Neither P00 or P10 can be built in with the pull-up resistor.

Any of these pins assumes the input port mode at RESET input.

Table 2-3 Port 0’s, 1’s Dual-Function Pins

Port 0	Dual-Function		Pin Port 1	Dual-Function Pin
P00			P10	INT0
P01			P12	INT2
		SCK
P02	SO/SB0
P03		SI

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