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TMP91C824
91C824-14
3.3.1
Block diagram of system clock
Clock gear
SYSCR1<SYSCK>
TMRA0 to 3
SYSCR0
<PRCK1, PRCK 0>
selector
fs
f
OSCH
Low-Frequency
oscillator
XT1
XT2
SYSCR0
<XTEN, RXTEN>
Warming up timer (High/Low frequency
oscillator), Lock up timer (DFM)
SYSCR0<WUEF>
SYSCR2<WUPTM1, WUPTM 0>
DFMCR0<ACT1, ACT 0, DLUPTM>
X1
X2
Clock Doubler
(DFM)
f
DFM
=
f
OSCH
×
4
÷
2
÷
16
÷
4
fc/16
fc/8
fc/4
fc/2
fc
DFMCR0<ACT1, ACT 0>
SYSCR1<GEAR2, GEAR 0>
÷
2
÷
4
fc/16
f
FPH
f
SYS
÷
2
f
SYS
CPU
RAM
ADC
Interrupt
controller
WDT
I/O ports
prescaler
φ
T0
SIO0 to1
SBI
RTC
φ
T
fs
φ
T0
fs
φ
T
SYSCR0
<XEN, RXTEN>
High-Frequency
oscillator
÷
8
prescaler
prescaler
MLD/ALM
Figure 3.3.2 Block Diagram of System clock