
Under
development
Tentative Specifications REV.C1
Specifications in this manual are tentative and subject to change.
Mitsubishi microcomputers
M30100/M30101/M30102 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Timer
70
In programmable waveform generation mode, if the value of the timer Z primary, timer Z secondary,
or primary or secondary waveform extension control bit is altered, control is exercised in such a way
that the output waveform changes from the beginning of the waveform period (i.e., the timer Z primary
waveform period).
To alter the count value, set the timer Z secondary, primary waveform extension control bit, second-
ary waveform extension control bit, and finally the timer Z primary. The values thus set are reflected
collectively at the beginning of the next waveform period after writing to the timer Z primary. (Even
when writing while the timer is idle, the timer Z primary is always the last register to be written.)
In programmable waveform generation mode, an interrupt is generated by only an underflow of the
secondary period.
Precaution
Change of set count values
When altering the set count values in programmable waveform generation mode, note that the set
value of the timer Z secondary and those of the primary and secondary waveform extension control
bits are made effective by setting the timer Z primary. Therefore, even when the set value of the timer
Z primary does not need to be altered, be sure to write the already set value to the timer Z primary
again.
Use of the waveform extend function
The waveform extend function based on timer Z waveform extension control bits is useful only when
the value “0016” is set in prescaler Z. If any other value is set in prescaler Z, always be sure to set the
timer Z primary waveform extension and timer Z secondary waveform extension control bits to 0. Note
also that if timer Y underflow is selected for the count source, the waveform extend function cannot be
used either.
Timer Z write mode
When operating in programmable waveform generation mode, always be sure to set the timer Z write
control bit to 1, thereby choosing to write to the reload register.
(3) Programmable one-shot generation mode
In programmable one-shot generation mode, upon software command or external trigger input, the
microcomputer outputs the one-shot pulse based on the timer Z primary set value from the TZOUT pin.
When operating in this mode, always be sure to set the timer Z write control bit to 1, thereby choosing
to write to only the reload registers. In this mode, said pin is always directed for output regardless of
how the direction register for the port P31 that is shared with the output pin is set. The timer Z second-
ary is unused in this mode.
The polarity of the output waveform is set by using the timer Z output level latch. If the timer Z output
level latch is set to 0, the microcomputer outputs a high pulse for the period equal to the set value of
timer Z primary. If the timer Z output level latch is set to 1, the microcomputer outputs a low pulse for
the period equal to the set value of timer Z primary.
In programmable one-shot generation mode, timer Z is readied to receive a software command or a
trigger from the external INT0 pin by writing 1 to the timer Z count start flag after setting the count
value. When a trigger from the external INT0 pin is used, set the INT0 input enable bit (INT0EN) to "1
." (Timer Z still remains idle at the time the timer Z count start flag is set to 1.)