NEC PD78078 User Manual

Data set previously in the real-time output buffer register can be transferred to the output latch by hardware

concurrently with timer interrupt request or external interrupt request generation, then output externally.  This is

called the real-time output function.  The pins that output data externally are called real-time output ports.

By using a real-time output, a signal which has no jitter can be output.  This port is therefore suitable for control

of stepping motors, etc.

Port mode/real-time output port mode can be specified bit-wise.

The real-time output port consists of the following hardware.

Item

Configuration

Register

Real-time output buffer register (RTBL, RTBH)

Control register

Port mode register 12 (PM12)

Real-time output port mode register (RTPM)

Real-time output port control register (RTPC)

Internal Bus

Real-time Output 
Port Control 
Register

EXTR

BYTE

Output Trigger
Control Circuit

Port Mode
Register 12
(PM12)

Real-time Output
Buffer Register
Higher 4 Bits
       (RTBH)

Real-time Output
Buffer Register
Lower 4 Bits
       (RTBL)

Output Latch

P120

P127

Real-time Output port

Mode Register (RTPM)

INTP2

INTTM1

INTTM2