MOS Integrated Circuit Data Sheet

194
µ PD17062
15.3 GENERAL-PURPOSE I/O PORTS (P0A, P0B, P1B, P1C)
15.3.1 Configuration of I/O Ports
In the following, (1) to (3) explain the configuration of the I/O ports.
(1) P0A (P0A
3, P0A2 pins)
P0B (P0B
3, P0B2, P0B1, P0B0 pins)
P1B (P1B
3, P1B2, P1B1, P1B0 pins)
P1C (P1C
3, P1C2, P1C1 pins)
(2) P0A (P0A1, P0A0 pins)
15.3.2 How to Use I/O Ports
An I/O port is set as an input or output port according to the contents of each I/O selection register of P0A,
P0B, P1B, and P1C of the control register.
I/O of the bit I/O port (P0A, P0B, P1B) can be set in 1-bit (1-pin) units. I/O of the group I/O port (P0C) can
be set in 3-bit (3-pin) units.
Output data is set and input data is read when a data write instruction or data read instruction is executed
in the corresponding port register.
Section 15.3.3 describes the I/O selection register of each port.
Sections 15.3.4 and 15.3.5 explain the use of an input port and output port.
V DD
V DD
OR
AND
1
0
I/O switching flag
Output
latch
Write
instruction
Port register
(1 bit)
Read
instruction
RESET (except P1C)
Read instruction (P1C only)
V DD
AND
RESET
I/O switching flag
Output
latch
Write
instruction
Port register
(1 bit)
Read
instruction