Specifications

I-42 EPSON S1C62N82 TECHNICAL HARDWARE
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (I/O Ports)
The output specification during output mode (IOC = 1) of the
I/O port can be set with the mask option for either comple-
mentary output or Pch open drain output. This setting can
be performed for each bit of the I/O port. However, when
Pch open drain output has been selected, voltage in excess
of the supply voltage must not be applied to the port.
Table 4.5.1 lists the I/O port control bits and their ad-
dresses.
Mask option
Control of I/O port
Table 4.5.1 I/O port control bits
I/O port data (0F6H)
I/O port data can be read and output data can be written
through the port.
• When writing data
When 1 is written: High level
When 0 is written: Low level
When an I/O port is set to the output mode, the written
data is output from the I/O port pin unchanged. When 1
is written as the port data, the port pin goes high (VDD),
and when 0 is written, the level goes low (VSS). Port data
can also be written in the input mode.
P00–P03
Address Comment
Register
D3 D2 D1 D0 Name SR 1 0
0F6H
P03 P02 P01 P00 P03
P02
P01
P00
–
–
–
–
I/O port (P00–P03)
High
High
High
High
Low
Low
Low
Low
R/W
0FCH
CLKCHG OSCC 0 IOC CLKCHG
OSCC
0
IOC
0
0
0
CPU clock switch
OSC3 oscillator ON/OFF
I/O port P00–P03 Input/Output
OSC3
ON
Output
OSC1
OFF
Input
R/W
R/W R