
26
MPC8272 PowerQUICC II Family Hardware Specifications
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
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MOTOROLA
Clock Configuration Modes
1101_000
100.0 133.3
2.5
250.0 333.3
3
300.0 400.0
5
50.0
66.7
1101_001
100.0 133.3
2.5
250.0 333.3
3.5
350.0 466.6
5
50.0
66.7
1101_010
100.0 133.3
2.5
250.0 333.3
4
400.0 533.3
5
50.0
66.7
1101_011
100.0 133.3
2.5
250.0 333.3
4.5
450.0 599.9
5
50.0
66.7
1101_100
100.0 133.3
2.5
250.0 333.3
5
500.0 666.6
5
50.0
66.7
1101_101
125.0 166.7
2
250.0 333.3
3
375.0 500.0
5
50.0
66.7
1101_110
125.0 166.7
2
250.0 333.3
4
500.0 666.6
5
50.0
66.7
1110_000
100.0 133.3
3
300.0 400.0
3.5
350.0 466.6
6
50.0
66.7
1110_001
100.0 133.3
3
300.0 400.0
4
400.0 533.3
6
50.0
66.7
1110_010
100.0 133.3
3
300.0 400.0
4.5
450.0 599.9
6
50.0
66.7
1110_011
100.0 133.3
3
300.0 400.0
5
500.0 666.6
6
50.0
66.7
1110_100
100.0 133.3
3
300.0 400.0
5.5
550.0 733.3
6
50.0
66.7
1100_000
Reserved
1100_001
Reserved
1100_010
Reserved
1
The “l(fā)ow” values are the minimum allowable frequencies for a given clock mode. The minimum bus frequency
guarantees the required minimum CPU operating frequency. Minimum CPU frequency is determined by the clock
mode. For modes with a CPU multiplication factor
≤
3, the minimum CPU frequency is 125 MHz or 150 MHz, as
shown in the table. For modes with a CPU multiplication factor
≥
3.5, the minimum CPU frequency is 250 MHz.
The “high” values are for the purpose of illustration only. Users must select a mode and input bus frequency so
that the resulting configuration does not exceed the frequency rating of the user’s device.
2
PCI_MODCK determines the PCI clock frequency range. Refer to Table 16 for lower range configurations.
3
MODCK_H = hard reset configuration word [28–31] (refer to Section 5.4 in the
MPC8260 User’s Manual
).
MODCK[1-3] = three hardware configuration pins.
4
CPM multiplication factor = CPM clock/bus clock
5
CPU multiplication factor = Core PLL multiplication factor
Table 15. Clock Configurations for PCI Host Mode (PCI_MODCK=0)
1, 2
(continued)
Mode
3
Bus Clock
(MHz)
CPM
Multiplication
Factor
4
CPM Clock
(MHz)
CPU
Multiplication
Factor
5
CPU Clock
(MHz)
PCI
Division
Factor
PCI Clock
(MHz)
MODCK_H-
MODCK[1-3]
Low
High
Low
High
Low
High
Low
High
F
Freescale Semiconductor, Inc.
n
.