UPD75328 Datasheet, PDF (21/66 Pages) NEC – 4-BIT SINGLE-CHIP MICROCOMPUTER

µPD75328
5.4 BASIC INTERVAL TIMER
The µPD75328 is provided with the 8-bit basic interval timer. The basic interval timer has these functions:
• Interval timer operation which generates a reference time interrupt
• Watchdog timer application which detects a program runaway
• Selects the wait time for releasing the standby mode and counts the wait time
• Reads out the count value
From the
clock generator
fX/2⁵
fX/2⁷
fX/2⁹
fX/2¹²
MPX
Clear
Clear
Basic interval timer
(8-bit frequency divider circuit)
BT
Set
signal
BT
interrupt
request flag ^Vector
interrupt
request
IRQBT ^signal
3
BTM3 BTM2 BTM1 BTM0 BTM
SET1*
4
8
Internal bus
Wait release signal
for standby release
Remarks : *: Instruction execution
Fig. 5-3 Basic Interval Timer Configuration
21