NEC PD17062 Manuale Utente

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In the following, (1) to (3) explain the configuration of the 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