UPD784218 Datasheet, PDF (44/92 Pages) NEC – 16-/8-BIT SINGLE-CHIP MICROCONTROLLERS

µPD784218, 784218Y
8.9 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 (@ 12.5 MHz operation with main system clock)
Figure 8-15. Block Diagram of Buzzer Output Function
fXX/2¹⁰
fXX/2¹¹
fXX/2¹²
fXX/2¹³
Output controller
BUZ
8.10 Edge Detection Function
The interrupt input pins (INTP0, INTP1, NMI/INTP2, INTP3 through INTP6) 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 function is also provided
to prevent erroneous detection due to noise.
Pin Name
NMI
INTP0 to INTP6
Detectable Edge
Either or both of rising and falling edges
Noise Reduction
By analog delay
8.11 Watch Timer
The watch timer has the following functions:
• 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
using the 32.768 kHz subsystem clock.
(2) Interval timer
The interval timer generates an interrupt request (INTTM3) at preset time intervals.
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Data Sheet U12304EJ2V0DS00