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TMP92CM22
2007-02-16
92CM22-19
3.3.5 Noise Reduction Circuits
Noise reduction circuits are built in for reduction EMI (Unnecessary radius noise) and
reinforcement EMS (Measure of endure noise), allowing implementation of the following
features.
(1) Reduced drivability for high-frequency oscillator
(2) Single drive for high-frequency oscillator
(3) SFR protection of register contents
These functions need setting by EMCCR0 to EMCCR2.
(1) Reduced drivability for high-frequency oscillator
(Purpose)
Reduces noise and power for oscillator when connect oscillator to outside.
(Block diagram)
(Setting method)
The drivability of the oscillator is reduced by writing “0” to
EMCCR0<DRVOSCH> register. By reset, <DRVOSCH> is initialized to “1” and
the oscillator starts oscillation by normal drivability when the power supply is on.
Note: When use drivability reduction function of oscillator, please use in case of
f
OSCH
= 4 MHz to 10 MHz condition.
f
OSCH
Oscillation enable (
><+ EXTINEMCCR0STOP
)
EMCCR0<DRVOSCH>
X1 pin
X2 pin
C1
C2
Oscillator