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SUMMARY OF PRECAUTIONS
Appendix 4-17
Appendix 4
Rev.1.10 REJ09B0123-0110 Apr.06.07
32192/32195/32196 Group Hardware Manual
Appendix 4.9 Notes on Multijunction Timers
Appendix 4.9.16 0% or 100% Duty-Cycle Wave Output during PWM Output and Single-
shot PWM Output Modes
During PWM output or single-shot PWM output mode, if the value "H'FFFF" is written to the reload 0 or reload 1
register, F/F output will not be inverted, making it possible to produce a 0% or 100% duty-cycle PWM output.
Because determination is made to see if the reload value is "H'FFFF" during PWM output or single-shot PWM
output mode, following precautions must be observed.
(1) Because the counter counts one even when detecting 0% or 100% duty-cycle, one of the two reload
registers must have set in it one less than the intended value in order for a constant-cycle waveform to be
produced.
Example: If the desired output cycle is 10 counts
Cycle ratio
50% : 50%
80% : 20%
90% : 10%
100% : 0%
Count ratio
5 : 5
8 : 2
9 : 1
10 : 0
Register set values
0004 : 0004
0007 : 0001
0008 : 0000
0009 : FFFF
Because the counter counts n + 1, the values actually set in the
respective registers must be one less than the intended value.
(2) Because setting the value "H'FFFF" in the reload register produces a 0% or 100% duty-cycle, it is impos-
sible to count the exact "H'FFFF."
(3) Setting the value "H'FFFF" in both reload 0 and reload 1 registers is inhibited.
(4) Writing the value "H'FFFF" to the counter while in operation is inhibited.
(5) Even for a 0% or 100% duty-cycle, interrupt requests and startup registers to other timers are generated.
(6) Because a 0% or 100% duty-cycle needs to be determined when reloading the counter, there is a one count
clock equivalent delay before F/F is inverted and an interrupt or DMA transfer request is generated. How-
ever, startup requests to other timers are not delayed.
0008: FFFF
The counter counts one without inverting
F/F output after detecting "FFFF." For
this reason, the value to be set in the
register must be "0008," and not "0009."
Appendix 4.9.15 Notes on using TOU continuous output mode
The following describes precautions to be observed when using TOU continuous output mode.
If the timer is enabled by external input in the same clock period as count is disabled by writing to the enable
bit, the latter has priority so that count is disabled.
If the counter is accessed for read at the cycle of underflow, the counter value is read out as H'FF FFFF but
changes to “reload register value -1” at the next count clock timing.
Because the timer operates synchronously with the count clock, up to one count clock-dependent delay is
generated before F/F output is inverted after writing the enable bit.