4524_M Datasheet, PDF (213/310 Pages) Renesas Technology Corp – 4-BIT CISC SINGLE-CHIP MICROCOMPUTER 720 FAMILY / 4500 SERIES

4524 Group
APPLICATION
2.3 Timers
2.3.4 Notes on use
(1) Prescaler
Stop counting and then execute the TABPS instruction to read from prescaler data.
Stop counting and then execute the TPSAB instruction to set prescaler data.
(2) Count source
Stop timer 1, 2, 3, 4 or LC counting to change its count source.
(3) Reading the count values
Stop timer 1, 2, 3 or 4 counting and then execute the TAB1, TAB2, TAB3 or TAB4 instruction to
read its data.
(4) Writing to the timer
Stop timer 1, 2, 3, 4 or LC counting and then execute the T1AB, T2AB, T3AB, T4AB or TLCA
instruction to write its data.
(5) Writing to reload register R1, reload register R3 and reload register R4H
When writing data to reload register R1 while timer 1 is operating respectively, avoid a timing when
timer 1 underflows.
When writing data to reload register R3 while timer 3 is operating respectively, avoid a timing when
timer 3 underflows.
When writing data to reload register R4H while timer 4 is operating respectively, avoid a timing when
timer 4 underflows.
(6) Timer 4
• Avoid a timing when timer 4 underflows to stop timer 4.
• When “H” interval extension function of the PWM signal is set to be “valid”, set “0116” or more to
reload register R4H.
(7) Timer 5
Stop timer 5 counting to change its count source.
(8) Timer input/output pin
• Set the port C output latch to “0” to output the PWM signal from C/CNTR1 pin.
(9) Watchdog timer
• The watchdog timer function is valid after system is released from reset. When not using the
watchdog timer function, stop the watchdog timer function and execute the DWDT instruction, the
WRST instruction continuously, and clear the WEF flag to “0”.
• The watchdog timer function is valid after system is returned from the power down state. When not
using the watchdog timer function, stop the watchdog timer function and execute the DWDT instruction
and the WRST instruction continuously every system is returned from the power down state.
• When the watchdog timer function and power down function are used at the same time, initialize
the flag WDF1 with the WRST instruction before system enters into the power down state.
(10) Pulse width input to CNTR0 pin, CNTR1 pin
Refer to section “3.1 Electrical characteristics” for rating value of pulse width input to CNTR0 pin,
CNTR1 pin.
Rev.2.00 Aug, 06 2004
REJ09B0107-0200Z
2-49