Platform Power Delivery Guidelines
R
264
Intel
®
855PM Chipset Platform Design Guide
Figure 145. Decoupling Capacitors Placement and Connectivity
Vdd
Vdd
1
38
19
51
52
53
54
55
56
39
18
40
41
42
43
44
45
46
47
48
49
50
17
16
15
14
13
12
10
11
9
8
7
6
5
4
3
2
35
36
37
26
25
24
23
22
21
20
30
28
31
27
32
33
34
29
Vdd
Vdd
Vdd
Vdd
Vdd
48 MHz
Vss
48 MHz
Vss
Vss
Vdd
Vss
Vss
Vss
Vss Iref
Vss
XTAL_In
XTAL_Out
PCIF 0
PCIF 2
PCIF 1
PCI 0
PCI 3
PCI 2
PCI 1
PCI 6
PCI 5
PCI 4
66Buff0
/ 3V66_2
66Buf
f1
/
3V66_
3
66Buf
f2
/
3V66_
4
66In /
3V66_5
PWRD
WN#
REF
0
S1
S0
CPU_Sto
p #
CPU
0
CPU
/0
CPU
1
CPU
/1
CPU
2
CPU
/2
Mult
0
IRE
F
S2
US
B
48
MHz
DO
T
48
MHz
3V66_1 /
VCH
PCI_Sto
p #
3V66
_0
SCL
K
Vs
s
Gr
ou
nd
Flo
od
Vs
s
Vd
d
SDAT
A
SCL
K
Vtt_Pwr
gd #
Vdd
A
Vss
A
Vs
s
Vss
Vss
Vss
Vss
Vdd
Vdd
Vdd
Vdd
Vdd
Vdd
C1
C2
VddA
Vss
C3
C4
C5
C6
VddA
VddA
Vss Plane Vias