MPC8270 MOTOROLA [Motorola, Inc], MPC8270 Datasheet - Page 26

• Manufacturer Part Number: MPC8270
• Description: PowerQUICC II Family Hardware Specifications
• Manufacturer: MOTOROLA [Motorola, Inc]

1
2
3
4
5
7.2
Table 16 and Table 17 show clock configurations for PCI host mode. The frequencies listed 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. In addition, note the following:
MODCK_H-MODCK[1-3]
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MODCK_H = hard reset configuration word [28–31]. MODCK[1-3] = three hardware configuration pins.
60x and local bus frequency. Identical to CLKIN.
CPM multiplication factor = CPM clock/bus clock
CPU multiplication factor = Core PLL multiplication factor
“Low” 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 166 MHz. The minimum CPM
frequency is 133 MHz.
For modes with a CPU multiplication factor ≥ 3.5, the minimum CPU frequency is 250 MHz. The minimum CPM
frequency is as shown in the table.
“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.
0111_011
0111_100
0111_101
0111_110
0111_111
1000_000
1000_001
1000_010
1000_011
1000_100
1000_101
1000_110
1100_000
1100_001
1100_010
1101_000
Mode
PCI Host Mode
2
Table 15. Clock Configurations for Local Bus Mode
MPC8280 PowerQUICC II™ Family Hardware Specifications
55.5
71.4
62.5
55.6
71.4
62.5
55.6
50.0
45.5
low
Bus Clock
(MHz)
133.3
133.3
133.3
133.3
114.3
114.3
114.3
114.3
114.3
high
3
Multiplication
Factor
CPM
3.5
3.5
3.5
3.5
3.5
3
3
3
3
4
166.7
133.0
133.0
133.0
250.0
218.8
194.4
175.0
159.1
low
CPM Clock
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
(MHz)
400.0
400.0
400.0
400.0
400.0
400.0
400.0
400.0
400.0
high
1
Multiplication
(Continued)
Factor
CPU
3.5
4.5
3.5
4.5
5.5
3
4
4
5
5
166.7
250.0
250.0
250.0
250.0
250.0
250.0
250.0
250.0
low
CPU Clock
MOTOROLA
(MHz)
400.0
466.7
533.3
600.0
400.0
457.1
514.3
571.4
628.6
high