Datasheet

Internal Clock Source (S08ICSV1)
MC9S08QD4 Series MCU Data Sheet, Rev. 6
124 Freescale Semiconductor
9.1.3.5 FLL Bypassed External (FBE)
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 FLL Bypassed External Low Power (FBELP)
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 Stop (STOP)
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 Block Diagram
Figure 9-2 is the ICS block diagram.
Figure 9-2. Internal Clock Source (ICS) Block Diagram
DCO
Filter
RDIV
TRIM
/ 2
9
External Reference
IREFS
Clock Source
Block
CLKS
n=0-7
/ 2
n
n=0-3
/ 2
n
Internal
Reference
Clock
BDIV
9
ICSLCLK
ICSOUT
ICSIRCLK
EREFS
RANGE
EREFSTEN
HGO
Optional
IREFSTEN
ICSERCLK
Internal Clock Source Block
LP
ICSFFCLK
ERCLKEN
IRCLKEN
DCOOUT
FLL
RDIV_CLK