NEC PD75402A Manuale Utente

The 

µ

PD75402A is equipped with an 8-bit basic interval timer which has the following functions:

(a)

Standard time generation (2 different time intervals)

(b)  Reading counter contents

This basic interval timer can also be used as a watchdog timer for the detection of inadvertent program looping.

The configuration of the basic interval timer is shown in Fig. 5-21.

From Clock
Generation
Circuit

f

xx

/2

5

f

xx

/2

9

MPX

BTM3 BTM2

1

1

4

SET1*

Internal Bus

8

Basic Interval Timer
( 8-Bit Frequency Divider)

Clear

Clear

Set

Bt
Interrupt
Request 
Flag

BT

IRQBT

Vectored
Interrupt
Request
Signal

BTM

Instruction execution