4524_M Datasheet, PDF (204/310 Pages) Renesas Technology Corp – 4-BIT CISC SINGLE-CHIP MICROCOMPUTER 720 FAMILY / 4500 SERIES

4524 Group
APPLICATION
2.3 Timers
(4) Timer operation: timer start by external input
Outline: The constant period can be measured by external input.
Specifications: Timer 3 operates by INT1 input as a trigger and an interrupt occurs after 1 ms.
Figure 2.3.7 shows the setting example of timer start.
(5) CNTR1 output control: PWM output control
Outline: The PWM output from CNTR1 pin can be performed by timer 4.
Specifications: Timer 4 divides the main clock frequency f(XIN) = 4.0 MHz and the waveform, which
“H” period is 0.875 µs of the 1.875 µs PWM periods, is output from CNTR1 pin.
Figure 2.3.2 shows the timer 4 operation and Figure 2.3.8 shows the setting example of PWM output
control.
(6) Timer operation: constant period counter by timer 5
Constant period time by the timer count value can be measured.
Outline: A clock with high accuracy can be set up by using a 32.768 kHz quartz-crystal oscillator.
Specifications: Timer 5 divides the sub-clock frequency f(XCIN) = 32.768 kHz and timer 5 interrupt
occurs every 250 ms.
Figure 2.3.9 shows the setting example of constant period counter by timer 5.
q CNTR1 output: valid (W43 = “1”)
PWM signal “H” interval extension function: valid (W42 = “1”) (Note)
Reload register R4L = “0316”
Reload register R4H = “0216”
Timer 4 count source
Timer 4 count value
(Reload register)
Timer 4 underflow signal
0316 0216 0116 0016 0216 0116 0016 0316 0216 0116 0016 0216 0116 0016 0316 0216 0116 0016 0216
(R4L)
(R4H)
(R4L)
(R4H)
(R4L)
(R4H)
PWM signal
Timer 4 start
3.5 clock
PWM period 7.5 clock
3.5 clock
PWM period 7.5 clock
Note: At PWM signal “H” interval extension function: valid, set “0116” or more to reload register R4H.
Fig. 2.3.2 Timer 4 operation
Rev.2.00 Aug, 06 2004
REJ09B0107-0200Z
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