
49
PC8265A PowerQUICC II
5336A–HIREL–08/03
PCI Mode
This section pertains to the PC8265A and the PC8266A only.
In PCI mode only, MODCK_HI[0:3] and PCI_MODCK come from the following external
pins:
PCI_MODCK = LGPL5
MODCK_HI[0:3] = {LGPL0,LGPL1,LGPL2,LGPL3}
Note:
The minimum Tval = 2 when PCI_MODCK = 1 and minimum Tval = 1 when
PCI_MODCK = 0; therefore, board designers should use clock configurations that fit this
condition to achieve PCI-compliant AC timing.
Notes:
1. Assumes MODCK_HI = 0000.
2. The frequency depends on the value of PCI_MODCK. If PCI_MODCK is high (logic ‘1’), the PCI frequency is divided by 2
(33 instead of 66 MHz, etc.)
Table 17 describes all possible clock configurations when using the PC8265A or the PC8266A’s internal PCI bridge in host
mode.
Table 16.
Clock Default Configurations in PCI Host Mode (MODCK_HI = 0000)
MODCK[1–
3]
(1)
Input Clock
Frequency
CPM
Multiplication
CPM
Frequency
Core
Multiplication
Core
Frequency
PCI Division
Factor
(2)
PCI
Frequency
(2)
000
66 MHz
2
133 MHz
2.5
166 MHz
2/4
66/33 MHz
001
66 MHz
2
133 MHz
3
200 MHz
2/4
66/33 MHz
010
66 MHz
2.5
166 MHz
3
200 MHz
3/6
55/28 MHz
011
66 MHz
2.5
166 MHz
3.5
233 MHz
3/6
55/28 MHz
100
66 MHz
2.5
166 MHz
4
266 MHz
3/6
55/28 MHz
101
66 MHz
3
200 MHz
3
200 MHz
3/6
66/33 MHz
110
66 MHz
3
200 MHz
3.5
233 MHz
3/6
66/33 MHz
111
66 MHz
3
200 MHz
4
266 MHz
3/6
66/33 MHz
Table 17.
Clock Configuration Modes in PCI Host Mode
MODCK_H –
MODCK[1–3]
Input Clock
Frequency
(1)
(Bus)
CPM
Multiplication
Factor
CPM
Frequency
Core
Multiplication
Factor
Core
Frequency
PCI Division
Factor
(2)
PCI
Frequency
(2)
0001_000
33 MHz
3
100 MHz
5
166 MHz
3/6
33/16 MHz
0001_001
33 MHz
3
100 MHz
6
200 MHz
3/6
33/16 MHz
0001_010
33 MHz
3
100 MHz
7
233 MHz
3/6
33/16 MHz
0001_011
33 MHz
3
100 MHz
8
266 MHz
3/6
33/16 MHz
0010_000
33 MHz
4
133 MHz
5
166 MHz
4/8
33/16 MHz
0010_001
33 MHz
4
133 MHz
6
200 MHz
4/8
33/16 MHz
0010_010
33 MHz
4
133 MHz
7
233 MHz
4/8
33/16 MHz
0010_011
33 MHz
4
133 MHz
8
266 MHz
4/8
33/16 MHz
0011_000
(3)
33 MHz
5
166 MHz
5
166 MHz
5
33 MHz
0011_001
(3)
33 MHz
5
166 MHz
6
200 MHz
5
33 MHz