Toshiba TLCS-900/H1 Series Manual page 34

(2) Reduced drivability for low-frequency oscillator
(Purpose)
Reduces noise and power for oscillator when a resonator is used.
(Block diagram)
C1
Resonator
C2
(Setting method)
The drive ability of the oscillator is reduced by writing 0 to the
EMCCR0<DRVOSCL> register. At reset, <DRVOSCL> is initialized to "1".
(3) Single drive for high-frequency oscillator
(Purpose)
Remove the need for twin drives and prevent operational errors caused by noise
input to X2 pin when an external oscillator is used
(Block diagram)
X1 pin
(Setting method)
The oscillator is disabled and starts operation as buffer by writing "1" to
EMCCR0<EXTIN> register. X2 pin's output is always "1".
At reset, <EXTIN> is initialized to "0".
XT1 pin
XT2 pin
X2 pin
92CH21-32
Enable oscillation
EMCCR0<DRVOSCL>
f
S
.
f
OSCH
Enable oscillation
EMCCR0<DRVOSCH>
TMP92CH21
2009-06-19