NEC switch Network Card User Manual


 
CHAPTER 2 PIN FUNCTIONS
User’s Manual U12978EJ3V0UD
29
(2) Non-port pins
Pin Name I/O Function After Reset Alternate
Function
INTP0 Input External interrupt request input for which valid edge (rising
and/or falling edge) can be specified
Input P26/TI01/TO01
KR00 to
KR07
Input Input for detecting key return signals Input P40 to P47
NC No connection. Can be left open.
REGC Internally generated power supply for driving USB
driver/receiver. Connect this pin to V
SS
via a 22
µ
F capacitor.
——
RESET
Input System reset input Input
SCK10
I/O Serial clock input/output for serial interface Input P20
SI10 Input Serial data input for serial interface Input P22
SO10 Output Serial data output for serial interface Input P21
TI01 Input External count clock input to 8-bit timer TM01 Input P26/INTP0/TO01
TO01 Output Output from 8-bit timer TM01 Input P26/INTP0/TI01
USBDM I/O Serial data input/output (negative side) for USB function. The
pull-up resistor (1.5 k) for the USBDM pin must be
connected to the REGC pin.
Input
USBDP I/O Serial data input/output (positive side) for USB function Input
V
DD0
Positive power supply for ports
V
DD1
Positive power supply for circuits other than ports
V
SS0
Ground potential for ports
V
SS1
Ground potential for circuits other than ports
X1 Input Input
X2
Crystal resonator connection to for system clock oscillator
——
IC Internally connected directly to V
SS0
——
V
PP
Sets flash memory programming mode. Apply high voltage
when a program is written or verified.
——