
PowerQUICC III MPC8555E and MPC8541E Bring-Up Guidelines, Rev. 5
Freescale Semiconductor
7
Clocking
Figure 2. Clock Subsystem Block Diagram
Table 3. Clocking Quick Reference
Functional Block
Clock Derivation
Core (including L1)
CCB [2, 2.5, 3, 3.5]
DDR
CCB / 2
I
2
C
CCB / (I2CFDR ratio)
L2 cache, CPM
CCB
Local Bus
CCB / [2,4,8]
Core PLL
Platform PLL
DLL
LSYNC_IN
LSYNC_OUT
LCLK0
LCLK1
core_clk
e500 Core
CCB_clk
to Rest of the Device
SYSCLK
CCB_clk
cfg_sys_pll[0:3]
cfg_core_pll[0:1]
2
4
LBC
PCI1 PLL
PCI2 PLL
PCI 2
PCI 1
PCI1_CLK
cfg_pci1_clk
cfg_pci2_clk
PCI2_CLK
÷
2
÷
n
DRAM
MCK[0:5]
MCK[0:5]
6
6
DDR
Controller
Clock
Control