NEC PD78F9488 Manuale Utente

CHAPTER  2   PIN  FUNCTIONS 

 

User’s Manual  U15331EJ4V1UD

These pins constitute a 5-bit I/O port.  In addition, they also function as timer I/O, external interrupt input, and 

remote control receive data input

. 

Port 3 can be specified in the following operation modes in 1-bit units. 
 
(1) Port 

In this mode, P30 to P34 function as a 5-bit I/O port.  Port 3 can be set in the input or output port mode in 1-
bit units by port mode register 3 (PM3).  When used as an input port, use of an on-chip pull-up resistor can 
be specified by pull-up resistor option register B3 (PUB3) in 1-bit units. 

 
(2) Control 

In this mode, P30 to P34 function as timer I/O, external interrupt input, and remote control receive data 
input

. 

 

These are the external clock input pins of timers 60 and 61. 

 

These are the timer output pins of timers 20, 50, 60, and 61. 

 

This is the capture edge input pin of 16-bit timer 20. 

 

These are external interrupt input pins for which valid edges (rising edge, falling edge, or both rising and 
falling edges) can be specified. 

 

This is the data input pin of the remote controller receiver. 
 
Note 

µ

PD789489 and 78F9489 only 

 
2.2.5  P50 to P53 (Port 5) 

These pins constitute as a 4-bit N-ch open-drain I/O port.  Port 5 can be set in the input or output port mode in 1-

bit units by port mode register 5 (PM5).  In the mask ROM version, use of an on-chip pull-up resistor can be specified 
by a mask option in 1-bit units.