UPD784224 Datasheet, PDF (44/92 Pages) NEC – 16/8-BIT SINGLE-CHIP MICROCONTROLLERS

µPD784224, 784225, 784224Y, 784225Y
7.9 Buzzer Output Function
Clocks of the following frequencies can be output as buzzer output.
• 1.5 kHz/3.1 kHz/6.1 kHz/12.2 kHz (main system clock: 12.5 MHz)
Figure 7-15. Block Diagram of Buzzer Output Function
fXX/2¹⁰
fXX/2¹¹
fXX/2¹²
fXX/2¹³
Output controller
BUZ
7.10 Edge Detection Function
The interrupt input pins (INTP0, INTP1, NMI/INTP2, INTP3 to INTP5) are used not only to input interrupt requests
but also to input trigger signals to the internal hardware units. Because these pins operate at an edge of the input
signal, they have a function to detect an edge. Moreover, a noise reduction circuit is also provided to prevent
erroneous detection due to noise.
Pin Name
NMI
INTP0 to INTP5
Detectable Edge
Either or both of rising and falling edges
7.11 Watch Timer
The watch timer has the following functions:
Noise Reduction
By analog delay
—
• Watch timer
• Interval timer
The watch timer and interval timer functions can be used at the same time.
(1) Watch timer
The watch timer sets the WTIF flag of the interrupt control register (WTIC) at time intervals of 0.5 seconds
by using the 32.768-kHz subsystem clock.
(2) Interval timer
The interval timer generates an interrupt request (INTTM3) at predetermined time intervals.
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Data Sheet U12376EJ1V0DS00