UPD75518 Datasheet, PDF (75/180 Pages) NEC – 4 BIT SINGLE-CHIP MICROCOMPUTER

µPD75518(A)
4.7 TIMER/PULSE GENERATOR
(1) Timer/pulse generator functions
The µPD75518(A) contains one channel for a timer/pulse generator that can be used as a timer or a pulse
generator. It has the following functions:
(a) Functions available when the timer/pulse generator is used in the timer mode
• 8-bit interval timer operation using one of five clock sources (occurrence of IRQTPG)
• Square wave output to the PPO pin
(b) Functions available when the timer/pulse generator is used in the PWM pulse generation mode
• PWM pulse output to the PPO pin with an accuracy of 14 bits (applicable for electronic tuning when
used as an D/A converter)
• Generation of interrupts at regular intervals (2¹⁵/fX)^Note
Note 2¹⁵/fX = 5.46 ms (at 6.0 MHz) or 7.81 ms (at 4.19 MHz)
If pulse output is unnecessary, the PPO pin can be used as a 1-bit output port.
Caution If the timer/pulse generator is operating when the STOP mode is set, it may malfunction. So
the timer/pulse generator must be disabled with the mode register in advance.
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