
Clocks and Power Control
MPC561/MPC563 Reference Manual, Rev. 1.2
8-2
Freescale Semiconductor
Figure 8-1 is a functional block diagram of the clock unit.
Figure 8-1. Clock Unit Block Diagram
2:1
SPLL
Clock
GCLK1 / GCLK2
GCLK1C / GCLK2C
VCOOUT
CLKOUT
3:1 MUX
XFC
TMBCLK
Lock
VDDSYN
Drivers
Driver
Main Clock
XTAL
EXTAL
3:1
MUX
RTC / PIT Clock
and Driver
Oscillator
MUX
TBCLK
(/4 or /16)
MODCK[1:3]
PITRTCLK
EXTCLK
2:1 MUX
Low
Power
Dividers
(1/2N)
/4 or
GCLK2
Backup Clock
Detector
Oscillator Loss
ENGCLK
VSSSYN
Drivers
System Clock
to RCPU and BBC
System
Low
Power
Control
/256