Freescale Semiconductor MCF52277 Reference Manual page 130

Clock Module
Clock Module
XTAL
EXTAL
FB_A16 (when
BOOTMOD = 10)
RTC_XTAL
RTC_EXTAL
SSICLKIN
USBCLKIN
Notes:
1
The output frequency of OUTDIV2 must equal the output frequency of OUTDIV1
2
The output frequency of OUTDIV3 must equal the output frequency of OUTDIV1.
3
The output frequency of OUTDIV5 must be 60MHz if it is used as the USB clock source.
4
The SDRAMC module is disabled in limp mode. The USB controller is essentially disabled, as well.
However, it is able to capture a wake-up event to bring the device out of limp mode.
5
The SDRAMC, real time clock, SSI, and USB contain some logic that uses the f
to the module-specific clock.
6
When loading boot code via the SBF, the device is clocked by the main oscillator (f
7
The LCD controller is also given a 32 Hz clock for the cursor blink counter.
7-2
FB_A19 (when
BOOTMODE = 10) or
MISCCR[LIMP]
PCR
OUTDIV1
f
vco
PCR OUTDIV2
[PFDR]
OUTDIV3
f
ref
OUTDIV5
÷2
CDR[LPDIV]
Serial Boot
Facility
MISCCR[RTCSRC]
Figure 7-1. Device Clock Connections
MCF52277 Reference Manual, Rev. 1
0
f
sys
1
f
sys/2
f
sys
CANCTRL[CLKSRC]
MISCCR
[SSISRC]
MISCCR[USBSRC]
÷
2.
clock, in addition
sys/2
).
ref
V2 ColdFire Core
SRAM/Cache
BDM
FB_CLK
FlexBus
SD_CLK
SDRAMC
SD_CLK
eDMA
LCD
Touchscreen/ADC
PWM
PIT
DMA Timers
DSPI_SCK
DSPI
UART
I2C
GPIO
FlexCAN
Real Time Clock
SSI
USB OTG
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