M16C62N Datasheet, PDF (142/213 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Programmable I/O Port
Mitsubishi microcomputers
M16C / 62N Group (80-pin)
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Programmable I/O Ports
The M16C/62N (80-pin version) group has 70 programmable input/output ports given below (except P85).
• P00-P07
• P20–P27
• P30–P37
• P40–P43
• P50–P57
• P60–P67
• P70, P71, P76, P77
• P80–P84, P86, P87 (P85 is input port)
• P90, P92–P97
• P100–P107
Note: P1, P44 to P47, P72 to P75, P91 are not connected to external pins.
Figures 1.18.1 to 1.18.4 show the programmable I/O ports. Figure 1.18.5 shows the I/O pins.
Each pin functions as a programmable I/O port and as the I/O for the built-in peripheral devices.
To use the pins as the inputs for the built-in peripheral devices, set the direction register of each pin to input
mode. When the pins are used as the outputs for the built-in peripheral devices (other than the D-A con-
verter), they function as outputs regardless of the contents of the direction registers. When pins are to be
used as the outputs for the D-A converter, do not set the direction registers to output mode. See the
descriptions of the respective functions for how to set up the built-in peripheral devices.
(1) Direction registers
Figure 1.18.6 shows the direction registers.
These registers are used to choose the direction of the programmable I/O ports. Each bit in these regis-
ters corresponds one for one to each I/O pin.
Note: There is no direction register bit for P85.
(2) Port registers
Figure 1.18.7 shows the port registers.
These registers are used to write and read data for input and output to and from an external device. A
port register consists of a port latch to hold output data and a circuit to read the status of a pin. Each bit
in port registers corresponds one for one to each I/O pin.
(3) Pull-up control registers
Figure 1.18.8 shows the pull-up control registers.
The pull-up control register can be set to apply a pull-up resistance to each block of 4 ports. When ports
are set to have a pull-up resistance, the pull-up resistance is connected only when the direction register is
set for input.
141