UPD75238GJ NEC [NEC], UPD75238GJ Datasheet - Page 61

• Manufacturer Part Number: UPD75238GJ
• Description: 4 BIT SINGLE-CHIP MICROCOMPUTER
• Manufacturer: NEC [NEC]

SET1
4.4 BASIC INTERVAL TIMER
(1) Configuration of the basic interval timer
(2) Basic interval timer functions
From the clock
generator
f
f
f
f
Fig. 4-23 shows the configuration of the basic interval timer.
The basic interval timer provides the following four functions:
(a) Reference time generation (four time intervals)
(b) Application of watchdog timer for detecting program crashes
(c) Selection of a wait time for releasing the standby mode, and counting
(d) Reading the count value
Note Instruction execution
X
X
X
X
Note
/2
/2
/2
/2
BTM3
5
7
9
12
BTM2
4
BTM1
MPX
3
Fig. 4-23 Configuration of the Basic Interval Timer
BTM0
BTM
(8-bit frequency divider circuit)
Internal bus
Basic interval timer
8
Clear
BT
Wait release
signal for standby
release
Set
BT interrupt
request flag
IRQBT
PD75238
Clear
Vector
interrupt
request
signal
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