NEC PD75402A - Manual (Page 77)

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CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.4 BASIC INTERVAL TIMER
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.
5.4.1 Basic Interval Timer Configuration
The configuration of the basic interval timer is shown in Fig. 5-21.
Fig. 5-21 Basic Interval Timer Configuration
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