M30622MA-XXXFP RENESAS [Renesas Technology Corp], M30622MA-XXXFP Datasheet - Page 461

• Manufacturer Part Number: M30622MA-XXXFP
• Description: 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY
• Manufacturer: RENESAS [Renesas Technology Corp]

Programmable I/O Ports
446
2.15 Programmable I/O Ports
2.15.1 Overview
Eighty-seven programmable I/O ports and one input-only port are available. I/O pins also serve as I/O
pins for built-in peripheral functions.
Each port has a direction register that defines the I/O direction and also has a port register for I/O data. In
addition, each port has a pull-up control register that defines pull-up in terms of 4 bits. The input-only port
has neither direction register nor pull-up control bit.
The following is an overview of the programmable I/O ports:
(1) Writing to a port register
(2) Reading a port register
(3) Effect of the protection register
(4) Input-only port
(5) Setting pull-up
With the direction register set to output, the level of the written values from each relevant pin is output
by writing to a port register. The output level conforms to CMOS output. Port P7
channel open drain. Writing to the port register, with the direction register set to input, inputs a value
to the port register, but nothing is output to the relevant pins. The output level remains floating.
With the direction register set to output, reading a port register takes out the content of the port regis-
ter, not the content of the pin. With the direction register set to input, reading the port register takes out
the content of the pin.
Data written to the direction register of P9 is affected by the protection register. The direction register
of P9 cannot be easily rewritten.
P8
be set to this port. As NMI cannot be disabled, an NMI interrupt occurs if a falling edge is input to P8
Use P8
The pull-up control bit allows setting of the pull-up, in terms of 4 bits, either in use or not in use. For the
four bits chosen, pull-up is effective only in the ports whose direction register is set to input. Pull-up is
not effective in ports whose direction register is set to output.
Do not set pull-up of corresponding pin when X
Pull-up can be set for P0 to P3, P4
to P3, P4
5
is used as the input-only port, it also serves as NMI. P8
5
for reading the level input at this time only.
0
to P4
3
, P5 in memory expansion and microprocessor modes.
_______
0
to P4
3
, P5 in only single-chip mode. Pull-up cannot be set for P0
CIN
_______
/X
_______
COUT
is set or a port is used as A-D input.
5
has no direction register. Pull-up cannot
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Mitsubishi microcomputers
M16C / 62 Group
0
and P7
1
are N
5
.