mc9s08qd4 Freescale Semiconductor, Inc, mc9s08qd4 Datasheet - Page 126

• Manufacturer Part Number: mc9s08qd4
• Description: Hcs08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Internal Clock Source (S08ICSV1)
9.1.3.5
In FLL bypassed external mode, the FLL is enabled and controlled by an external reference clock, but is
bypassed. The ICS supplies a clock derived from the external reference clock. The external reference clock
can be an external crystal/resonator supplied by an OSC controlled by the ICS, or it can be another external
clock source. The BDC clock is supplied from the FLL.
9.1.3.6
In FLL bypassed external low power mode, the FLL is disabled and bypassed, and the ICS supplies a clock
derived from the external reference clock. The external reference clock can be an external crystal/resonator
supplied by an OSC controlled by the ICS, or it can be another external clock source. The BDC clock is
not available.
9.1.3.7
In stop mode the FLL is disabled and the internal or external reference clocks can be selected to be enabled
or disabled. The BDC clock is not available and the ICS does not provide an MCU clock source.
9.1.4
Figure 9-2
126
is the ICS block diagram.
Block Diagram
RANGE
FLL Bypassed Externa
FLL Bypassed Externa
Stop (STOP)
HGO
IREFS
Figure 9-2. Internal Clock Source (ICS) Block Diagram
External Reference
Clock Source
n=0-7
RDIV
/ 2
Optional
Block
n
MC9S08QD4 Series MCU Data Sheet, Rev. 3
IREFSTEN
Reference
Internal
RDIV_CLK
TRIM
Clock
9
l (FBE)
l Low Power (FBELP)
EREFSTEN
EREFS
Filter
DCO
LP
FLL
ERCLKEN
IRCLKEN
9
Internal Clock Source Block
CLKS
DCOOUT
n=0-3
BDIV
/ 2
/ 2
n
ICSERCLK
ICSIRCLK
ICSOUT
ICSLCLK
ICSFFCLK
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