NEC switch User Manual

Page 33

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CHAPTER 2 PIN FUNCTIONS

User’s Manual U12978EJ3V0UD

33

2.3 Pin I/O Circuits and Recommended Connection of Unused Pins

Table 2-1 lists the types of I/O circuits for each pin and explains how unused pins are handled.

Figure 2-1 shows the configuration of each type of I/O circuit.

Table 2-1. Type of Pin I/O Circuit Recommended Connection of Unused Pins

Pin Name

I/O Circuit Type

I/O

Recommended Connection of Unused Pins

P00 to P07

P10 to P17

5-R

P20/ SCK10

P21/SO10

P22/SI10

P23, P24

8-C

P25

P26/INTP0/TI01/TO01

8-F

P40/ KR00 to

P47/ KR07

8-C

Input:

Independently connect to V

DD0

, V

DD1

, V

SS0

, or V

SS1

via a

resistor.

Output: Leave open.

USBDM

Connect to the REGC pin.

USBDP

24-A

I/O

Independently connect to V

SS0

or V

SS1

via a resistor.

RESET

2

Input

NC

Leave open.

REGC

Connect to USBDM pin.

IC

Connect directly to V

SS0

.

V

PP

Independently connect a 10 k

Ω pull-down resistor, or connect directly

to V

SS0

.

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