CHAPTER 1 INTRODUCTION
User’s Manual U16896EJ2V0UD
30
(q) Power-on-clear (POC) circuit
The power-on-clear circuit generates an internal reset signal at power on.
The power-on-clear circuit compares the supply voltage (V
DD
) and detection voltage (V
POC
), and generates
an internal reset signal when V
DD
< V
POC
.
(r) Ports
As shown below, the following ports have general-purpose port functions and control pin functions.
Port I/O
Alternate
Function
P0
7-bit I/O
NMI, external interrupt, timer output
P3
8-bit I/O
Serial interface, timer I/O, external interrupt, A/D converter trigger
P4
3-bit I/O
Serial interface
P5
6-bit I/O
Timer I/O, key interrupt function, real-time output function
P7
8-bit input
A/D converter analog input
P9
9-bit I/O
Serial interface, timer I/O, external interrupt, key interrupt function
PCM 2-bit
I/O
Clock
output
PDL 8-bit
I/O
−
