Table 7-4. Possible Clocking Ratios For Reference Clock Of 25Mhz - IBM PowerPC 405GP User Manual

Table 7·4. Possible Clocking Ratios for Reference Clock of 25 MHz
Strapping Options Calculated Values (MHz)
FWD CPu/PLB FBK M VCO CPU
PLB
By-pass<!
1
x
- -
refclk refclk
2
x
-
-
refclk refclkl2
3
x
- -
refclk refclkl3
4
x
-
-
refclk refclkl4
3 2 3 18 450
150 75
3
2 4 24 600 200 100
3 3
2 18 450 150 50
3 3 3 27 675 225 75
3 4 2 24 600 200 50
4 1 4 16 400 100 100
4 2 2 16 400 100 50
4 2 3 24 600 150 75
4 2 4 32 800
200 100
4 3
2 24 600 150 50
4 4
1 16 400 100 25
4 4 2 32 800
200
50
6 1
3
18 450 75 75
6 1 4 24 600 100 100
6 2 2 24 600 100 50
6 3 1 18 450 75
25
6 4 1 24 600 100 25
Note 1: x
=
don't care.
Note 2:
By-pass mode is designed for hardware emulator use only.
Contact your IBM representative for more information.
Note 3:
Not all PPC405GP parts support the frequencies shown. Check
PPC405GP Datasheet for supported CPU and PLB frequencies for
a specific part number.
7·6 PPC405GP User's Manual Preliminary