UPD75116H Datasheet, PDF (21/66 Pages) NEC – 4-BIT SINGLE-CHIP MICROCOMPUTER

µPD75116H,75117H
5.4 BASIC INTERVAL TIMER
The basic interval timer includes the following functions.
• It operates as an interval timer which generates reference time interrupts.
• It can be applied as a watchdog timer which detects when a program is out of control.
• Selects and counts wait times when the standby mode is released.
• It reads count contents.
Fig. 5-3 Basic Interval Timer Configuration
From Clock
Generator
fXX/2 ⁵
fXX/2⁷
fXX/2⁹
fXX/2¹²
MPX
Clear
Clear
Basic Interval Timer
(8-Bit Frequency Divider)
BT
Set _{BT Interrupt}
Request Flag
IRQBT
Vector
Interrupt
Request
Signal
3
BTM3 BTM2 BTM1 BTM0 BTM
Wait Release
Signal during
Standby Release
SET1*
4
8
Internal Bus
* SET1 indicates instruction execution.
5.5 TIMER/EVENT COUNTER
The µPD75117H incorporates two internal timer/event counter channels.
Timer/event counter channel 0 and channel 1 differ only in selectable count pulse (CP) and clock supply function
to serial interface and are the same in other configurations and functions.
• Operates as a programmable interval timer.
• Outputs square waves in the desired frequency to the PTOn pin.
• Operates as an event counter.
• Use of TIn pin as an external interrupt input pin.
• Divides the TIn pin input into N divisions and outputs it to the PTOn pin (frequency divider operation).
• Supplies a serial shift clock to the serial interface circuit. (channel 0 only)
• Count status read function.
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