
MPC8568E/MPC8567E PowerQUICC III Integrated Processor Hardware Specifications, Rev. 1
122
Freescale Semiconductor
Clocking
23.2
CCB/SYSCLK PLL Ratio
The CCB clock is the clock that drives the e500 core complex bus (CCB) and is also called the platform
clock. The frequency of the CCB is set using the following reset signals, as shown in
Table 83:SYSCLK input signal
Binary value on LA[28:31] at power up
Note that there is no default for this PLL ratio; these signals must be pulled to the desired values. Also note
that the DDR data rate is the determining factor in selecting the CCB bus frequency, since the CCB
frequency must equal the DDR data rate.
For specifications on the PCI_CLK, refer to the PCI 2.2 Specification.
Table 81. DDR/DDR2 Memory Bus Clocking Specifications
Characteristic
Maximum Processor Core Frequency
Unit
Notes
800, 1000, 1333 MHz
Min
Max
DDR/DDR2 Memory bus clock frequency
166
266
MHz
1, 2
Notes:
1. Caution: The CCB clock to SYSCLK ratio and e500 core to CCB clock ratio settings must be chosen such that the
resulting SYSCLK frequency, e500 core frequency, and CCB clock frequency do not exceed their respective maximum
or minimum operating frequencies.
2. The memory bus clock speed is half the DDR/DDR2 data rate, hence, half the platform clock frequency.
Table 82. Local Bus Clocking Specifications
Characteristic
Maximum Processor Core Frequency
Unit
Notes
800, 1000, 1333 MHz
Min
Max
Local bus clock speed (for Local Bus Controller)
25
166
MHz
1
Notes:
1. The Local bus clock speed on LCLK[0:2] is determined by CCB clock divided by the Local Bus PLL ratio programmed
in LCCR[CLKDIV]. See the reference manual for more information on this.
Table 83. CCB Clock Ratio
Binary Value of
LA[28:31] Signals
CCB:SYSCLK Ratio
Binary Value of
LA[28:31] Signals
CCB:SYSCLK Ratio
0000
16:1
1000
8:1
0001
Reserved
1001
9:1
0010
2:1
1010
10:1
0011
3:1
1011
Reserved
0100
4:1
1100
12:1