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Usage precaution
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Mitsubishi microcomputers
M30201 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
109
Timer X (pulse width modulation mode)
(1) The timer Xi interrupt request bit becomes “1” if setting operation mode of the timer in compliance with
any of the following procedures:
Selecting PWM mode after reset.
Changing operation mode from timer mode to PWM mode.
Changing operation mode from event counter mode to PWM mode.
Therefore, to use timer Xi interrupt (interrupt request bit), set timer Xi interrupt request bit to “0” after
the above listed changes have been made.
(2) Setting the count start flag to “0” while PWM pulses are being output causes the counter to stop
counting. If the TXi
INOUT
pin is outputting an “H” level in this instance, the output level goes to “L”, and
the timer Xi interrupt request bit goes to “1”. If the TXi
INOUT
pin is outputting an “L” level in this
instance, the level does not change, and the timer Xi interrupt request bit does not becomes “1”.
Timer X (pulse period/pulse width measurement mode)
(1) If changing the measurement mode select bit is set after a count is started, the timer Xi interrupt
request bit goes to “1”.
(2) When the first effective edge is input after a count is started, an indeterminate value is transferred to
the reload register. At this time, timer Xi interrupt request is not generated.
A-D Converter
(1) Write to each bit (except bit 6) of A-D control register 0, to each bit of A-D control register 1, and to bit
0 of A-D control register 2 when A-D conversion is stopped (before a trigger occurs).
In particular, when the Vref connection bit is changed from “0” to “1”, start A-D conversion after an
elapse of 1
μ
s or longer.
(2) When changing A-D operation mode, select analog input pin again.
(3) Using one-shot mode or single sweep mode
Read the correspondence A-D register after confirming A-D conversion is finished. (It is known by A-
D conversion interrupt request bit.)
(4) Using repeat mode, repeat sweep mode 0 or repeat sweep mode 1
Use the undivided main clock as the internal CPU clock.
Stop Mode and Wait Mode
(1) When returning from stop mode by hardware reset, RESET pin must be set to “L” level until main clock
oscillation is stabilized.
(2) When shifting to WAIT mode or STOP mode, the program stops after reading 8 bytes from the WAIT
instruction and the instruction that sets all clock stop bits to “1” in the instruction queue. Therefore,
insert a minimum of 8 NOPs after the WAIT instruction and the instruction that sets all clock stop bits
to “1”.