Internal Clock Source (S08ICSV3)

12.1.4Block Diagram

Figure 12-2is the ICS block diagram.

External Reference

 

 

 

 

Clock

 

 

 

 

 

EREFS

ERCLKEN

 

ICSERCLK

 

 

 

HGO

EREFSTEN

IRCLKEN

 

ICSIRCLK

 

 

 

 

 

 

 

RANGE

 

CLKS

BDIV

 

 

 

 

IREFSTEN

 

 

 

 

Internal

 

 

/ 2n

ICSOUT

 

DCOOUT

n=0–3

Reference

LP

 

Clock

 

 

ICSDCLK

 

 

FLL

/ 2

ICSLCLK

/ 2n

 

DCOL

 

 

Filter

DCOM

 

 

n=0–10

 

DCOH

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FTRIM

 

TRIM

 

 

RDIV

 

 

 

IREFS

 

 

 

DMX32

 

 

DRS

 

 

 

ICSFFCLK

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DRST

IREFST

CLKST

OSCINIT

 

 

 

 

 

 

 

 

 

 

 

 

Internal Clock Source Block

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 12-2. Internal Clock Source (ICS) Block Diagram

12.1.5Modes of Operation

There are seven modes of operation for the ICS: FEI, FEE, FBI, FBILP, FBE, FBELP, and stop.

12.1.5.1FLL Engaged Internal (FEI)

In FLL engaged internal mode, which is the default mode, the ICS supplies a clock derived from the FLL controlled by the internal reference clock. The BDC clock is supplied from the FLL.

12.1.5.2FLL Engaged External (FEE)

In FLL engaged external mode, the ICS supplies a clock derived from the FLL controlled by an external reference clock. The BDC clock is supplied from the FLL.

12.1.5.3FLL Bypassed Internal (FBI)

In FLL bypassed internal mode, the FLL is enabled and controlled by the internal reference clock, but is bypassed. The ICS supplies a clock derived from the internal reference clock. The BDC clock is supplied from the FLL.

MCF51QE128 MCU Series Reference Manual, Rev. 3

248

Freescale Semiconductor

Get the latest version from freescale.com

Page 248
Image 248
Freescale Semiconductor MCF51QE128RM manual 2is the ICS block diagram