| PCI Express as a high-bandwidth, low pin count, serial, interconnect technology. PCI Express architecture provides a high performance I/O infrastructure for Desktop Platforms with transfer rates starting at 2.5 Giga transfers per second over a x1 PCI Express lane for Gigabit Ethernet, TV Tuners, 1394a/b controllers, and general purpose I/O. PCI Express architecture provides a high performance graphics infrastructure for Desktop Platforms doubling the capability of existing AGP8x designs with transfer rates of 4.0 Gigabytes per second over a x16 PCI Express lane for graphics controllers. ExpressCard™ utilizing PCI Express interface, developed by the PCMCIA group for mobile computers. PCI Express Advanced Power Management features help to extend platform battery life and to enable users to work anywhere, without an AC power source.
The broad adoption of PCI Express in the mobile, enterprise and communication segments enables convergence through the re-use of a common interconnect technology.
PCI-E is a serial bus which uses two low-voltage differential LVDS pairs, at 2.5Gb/s in each direction [one transmit, and one receive pair]. PCI Express supports 1x [2.5Gbps], 2x, 4x, 8x, 12x, 16x, and 32x bus widths [transmit / receive pairs].
The differential pins [Lanes] listed in the pin out table above are LVDS which stands for: Low Voltage Differential Signaling.
PCI-Express 1x Connector Pin-Out
Pin |
Side B Connector |
Side A Connector |
# |
Name |
Description |
Name |
Description |
1 |
+12v |
+12 volt power |
PRSNT#1 |
Hot plug presence detect |
2 |
+12v |
+12 volt power |
+12v |
+12 volt power |
3 |
RSVD |
Reserved |
+12v |
+12 volt power |
4 |
GND |
Ground |
GND |
Ground |
5 |
SMCLK |
SMBus clock |
JTAG2 |
TCK |
6 |
SMDAT |
SMBus data |
JTAG3 |
TDI |
7 |
GND |
Ground |
JTAG4 |
TDO |
8 |
+3.3v |
+3.3 volt power |
JTAG5 |
TMS |
9 |
JTAG1 |
+TRST# |
+3.3v |
+3.3 volt power |
10 |
3.3Vaux |
3.3v volt power |
+3.3v |
+3.3 volt power |
11 |
WAKE# |
Link Reactivation |
PWRGD |
Power Good |
Mechanical Key |
12 |
RSVD |
Reserved |
GND |
Ground |
13 |
GND |
Ground |
REFCLK+ |
Reference Clock Differential pair |
14 |
HSOp(0) |
Transmitter Lane 0, Differential pair |
REFCLK- |
15 |
HSOn(0) |
GND |
Ground |
16 |
GND |
Ground |
HSIp(0) |
Receiver Lane 0, Differential pair |
17 |
PRSNT#2 |
Hotplug detect |
HSIn(0) |
18 |
GND |
Ground |
GND |
Ground |
PCI-Express 4x Connector Pin-Out
Pin |
Side B Connector |
Side A Connector |
# |
Name |
Description |
Name |
Description |
1 |
+12v |
+12 volt power |
PRSNT#1 |
Hot plug presence detect |
2 |
+12v |
+12 volt power |
+12v |
+12 volt power |
3 |
RSVD |
Reserved |
+12v |
+12 volt power |
4 |
GND |
Ground |
GND |
Ground |
5 |
SMCLK |
SMBus clock |
JTAG2 |
TCK |
6 |
SMDAT |
SMBus data |
JTAG3 |
TDI |
7 |
GND |
Ground |
JTAG4 |
TDO |
8 |
+3.3v |
+3.3 volt power |
JTAG5 |
TMS |
9 |
JTAG1 |
+TRST# |
+3.3v |
+3.3 volt power |
10 |
3.3Vaux |
3.3v volt power |
+3.3v |
+3.3 volt power |
11 |
WAKE# |
Link Reactivation |
PWRGD |
Power Good |
Mechanical Key |
12 |
RSVD |
Reserved |
GND |
Ground |
13 |
GND |
Ground |
REFCLK+ |
Reference Clock Differential pair |
14 |
HSOp(0) |
Transmitter Lane 0, Differential pair |
REFCLK- |
15 |
HSOn(0) |
GND |
Ground |
16 |
GND |
Ground |
HSIp(0) |
Receiver Lane 0, Differential pair |
17 |
PRSNT#2 |
Hotplug detect |
HSIn(0) |
18 |
GND |
Ground |
GND |
Ground |
19 |
HSOp(1) |
Transmitter Lane 1, Differential pair |
RSVD |
Reserved |
20 |
HSOn(1) |
GND |
Ground |
21 |
GND |
Ground |
HSIp(1) |
Receiver Lane 1, Differential pair |
22 |
GND |
Ground |
HSIn(1) |
23 |
HSOp(2) |
Transmitter Lane 2, Differential pair |
GND |
Ground |
24 |
HSOn(2) |
GND |
Ground |
25 |
GND |
Ground |
HSIp(2) |
Receiver Lane 2, Differential pair |
26 |
GND |
Ground |
HSIn(2) |
27 |
HSOp(3) |
Transmitter Lane 3, Differential pair |
GND |
Ground |
28 |
HSOn(0) |
GND |
Ground |
29 |
GND |
Ground |
HSIp(3) |
Receiver Lane 3, Differential pair |
30 |
RSVD |
Reserved |
HSIn(3) |
31 |
PRSNT#2 |
Hot plug detect |
GND |
Ground |
32 |
GND |
Ground |
RSVD |
Reserved |
PCI-Express 8x Connector Pin-Out
Pin |
Side B Connector |
Side A Connector |
# |
Name |
Description |
Name |
Description |
1 |
+12v |
+12 volt power |
PRSNT#1 |
Hot plug presence detect |
2 |
+12v |
+12 volt power |
+12v |
+12 volt power |
3 |
RSVD |
Reserved |
+12v |
+12 volt power |
4 |
GND |
Ground |
GND |
Ground |
5 |
SMCLK |
SMBus clock |
JTAG2 |
TCK |
6 |
SMDAT |
SMBus data |
JTAG3 |
TDI |
7 |
GND |
Ground |
JTAG4 |
TDO |
8 |
+3.3v |
+3.3 volt power |
JTAG5 |
TMS |
9 |
JTAG1 |
+TRST# |
+3.3v |
+3.3 volt power |
10 |
3.3Vaux |
3.3v volt power |
+3.3v |
+3.3 volt power |
11 |
WAKE# |
Link Reactivation |
PWRGD |
Power Good |
Mechanical Key |
12 |
RSVD |
Reserved |
GND |
Ground |
13 |
GND |
Ground |
REFCLK+ |
Reference Clock Differential pair |
14 |
HSOp(0) |
Transmitter Lane 0, Differential pair |
REFCLK- |
15 |
HSOn(0) |
GND |
Ground |
16 |
GND |
Ground |
HSIp(0) |
Receiver Lane 0, Differential pair |
17 |
PRSNT#2 |
Hotplug detect |
HSIn(0) |
18 |
GND |
Ground |
GND |
Ground |
19 |
HSOp(1) |
Transmitter Lane 1, Differential pair |
RSVD |
Reserved |
20 |
HSOn(1) |
GND |
Ground |
21 |
GND |
Ground |
HSIp(1) |
Receiver Lane 1, Differential pair |
22 |
GND |
Ground |
HSIn(1) |
23 |
HSOp(2) |
Transmitter Lane 2, Differential pair |
GND |
Ground |
24 |
HSOn(2) |
GND |
Ground |
25 |
GND |
Ground |
HSIp(2) |
Receiver Lane 2, Differential pair |
26 |
GND |
Ground |
HSIn(2) |
27 |
HSOp(3) |
Transmitter Lane 3, Differential pair |
GND |
Ground |
28 |
HSOn(0) |
GND |
Ground |
29 |
GND |
Ground |
HSIp(3) |
Receiver Lane 3, Differential pair |
30 |
RSVD |
Reserved |
HSIn(3) |
31 |
PRSNT#2 |
Hot plug detect |
GND |
Ground |
32 |
GND |
Ground |
RSVD |
Reserved |
33 |
HSOp(4) |
Transmitter Lane 4, Differential pair |
RSVD |
Reserved |
34 |
HSOn(4) |
GND |
Ground |
35 |
GND |
Ground |
HSIp(4) |
Receiver Lane 4, Differential pair |
36 |
GND |
Ground |
HSIn(4) |
37 |
HSOp(5) |
Transmitter Lane 5, Differential pair |
GND |
Ground |
38 |
HSOn(5) |
GND |
Ground |
39 |
GND |
Ground |
HSIp(5) |
Receiver Lane 5, Differential pair |
40 |
GND |
Ground |
HSIn(5) |
41 |
HSOp(6) |
Transmitter Lane 6, Differential pair |
GND |
Ground |
42 |
HSOn(6) |
GND |
Ground |
43 |
GND |
Ground |
HSIp(6) |
Receiver Lane 6, Differential pair |
44 |
GND |
Ground |
HSIn(6) |
45 |
HSOp(7) |
Transmitter Lane 7, Differential pair |
GND |
Ground |
46 |
HSOn(7) |
GND |
Ground |
47 |
GND |
Ground |
HSIp(7) |
Receiver Lane 7, Differential pair |
48 |
PRSNT#2 |
Hot plug detect |
HSIn(7) |
49 |
GND |
Ground |
GND |
Ground |
PCI-Express 16x Connector Pin-Out
Pin |
Side B Connector |
Side A Connector |
# |
Name |
Description |
Name |
Description |
1 |
+12v |
+12 volt power |
PRSNT#1 |
Hot plug presence detect |
2 |
+12v |
+12 volt power |
+12v |
+12 volt power |
3 |
RSVD |
Reserved |
+12v |
+12 volt power |
4 |
GND |
Ground |
GND |
Ground |
5 |
SMCLK |
SMBus clock |
JTAG2 |
TCK |
6 |
SMDAT |
SMBus data |
JTAG3 |
TDI |
7 |
GND |
Ground |
JTAG4 |
TDO |
8 |
+3.3v |
+3.3 volt power |
JTAG5 |
TMS |
9 |
JTAG1 |
+TRST# |
+3.3v |
+3.3 volt power |
10 |
3.3Vaux |
3.3v volt power |
+3.3v |
+3.3 volt power |
11 |
WAKE# |
Link Reactivation |
PWRGD |
Power Good |
Mechanical Key |
12 |
RSVD |
Reserved |
GND |
Ground |
13 |
GND |
Ground |
REFCLK+ |
Reference Clock Differential pair |
14 |
HSOp(0) |
Transmitter Lane 0, Differential pair |
REFCLK- |
15 |
HSOn(0) |
GND |
Ground |
16 |
GND |
Ground |
HSIp(0) |
Receiver Lane 0, Differential pair |
17 |
PRSNT#2 |
Hotplug detect |
HSIn(0) |
18 |
GND |
Ground |
GND |
Ground |
19 |
HSOp(1) |
Transmitter Lane 1, Differential pair |
RSVD |
Reserved |
20 |
HSOn(1) |
GND |
Ground |
21 |
GND |
Ground |
HSIp(1) |
Receiver Lane 1, Differential pair |
22 |
GND |
Ground |
HSIn(1) |
23 |
HSOp(2) |
Transmitter Lane 2, Differential pair |
GND |
Ground |
24 |
HSOn(2) |
GND |
Ground |
25 |
GND |
Ground |
HSIp(2) |
Receiver Lane 2, Differential pair |
26 |
GND |
Ground |
HSIn(2) |
27 |
HSOp(3) |
Transmitter Lane 3, Differential pair |
GND |
Ground |
28 |
HSOn(0) |
GND |
Ground |
29 |
GND |
Ground |
HSIp(3) |
Receiver Lane 3, Differential pair |
30 |
RSVD |
Reserved |
HSIn(3) |
31 |
PRSNT#2 |
Hot plug detect |
GND |
Ground |
32 |
GND |
Ground |
RSVD |
Reserved |
33 |
HSOp(4) |
Transmitter Lane 4, Differential pair |
RSVD |
Reserved |
34 |
HSOn(4) |
GND |
Ground |
35 |
GND |
Ground |
HSIp(4) |
Receiver Lane 4, Differential pair |
36 |
GND |
Ground |
HSIn(4) |
37 |
HSOp(5) |
Transmitter Lane 5, Differential pair |
GND |
Ground |
38 |
HSOn(5) |
GND |
Ground |
39 |
GND |
Ground |
HSIp(5) |
Receiver Lane 5, Differential pair |
40 |
GND |
Ground |
HSIn(5) |
41 |
HSOp(6) |
Transmitter Lane 6, Differential pair |
GND |
Ground |
42 |
HSOn(6) |
GND |
Ground |
43 |
GND |
Ground |
HSIp(6) |
Receiver Lane 6, Differential pair |
44 |
GND |
Ground |
HSIn(6) |
45 |
HSOp(7) |
Transmitter Lane 7, Differential pair |
GND |
Ground |
46 |
HSOn(7) |
GND |
Ground |
47 |
GND |
Ground |
HSIp(7) |
Receiver Lane 7, Differential pair |
48 |
PRSNT#2 |
Hot plug detect |
HSIn(7) |
49 |
GND |
Ground |
GND |
Ground |
50 |
HSOp(8) |
Transmitter Lane 8, Differential pair |
RSVD |
Reserved |
51 |
HSOn(8) |
GND |
Ground |
52 |
GND |
Ground |
HSIp(8) |
Receiver Lane 8, Differential pair |
53 |
GND |
Ground |
HSIn(8) |
54 |
HSOp(9) |
Transmitter Lane 9, Differential pair |
GND |
Ground |
55 |
HSOn(9) |
GND |
Ground |
56 |
GND |
Ground |
HSIp(9) |
Receiver Lane 9, Differential pair |
57 |
GND |
Ground |
HSIn(9) |
58 |
HSOp(10) |
Transmitter Lane 10, Differential pair |
GND |
Ground |
59 |
HSOn(10) |
GND |
Ground |
60 |
GND |
Ground |
HSIp(10) |
Receiver Lane 10, Differential pair |
61 |
GND |
Ground |
HSIn(10) |
62 |
HSOp(11) |
Transmitter Lane 11, Differential pair |
GND |
Ground |
63 |
HSOn(11) |
GND |
Ground |
64 |
GND |
Ground |
HSIp(11) |
Receiver Lane 11, Differential pair |
65 |
GND |
Ground |
HSIn(11) |
66 |
HSOp(12) |
Transmitter Lane 12, Differential pair |
GND |
Ground |
67 |
HSOn(12) |
GND |
Ground |
68 |
GND |
Ground |
HSIp(12) |
Receiver Lane 12, Differential pair |
69 |
GND |
Ground |
HSIn(12) |
70 |
HSOp(13) |
Transmitter Lane 13, Differential pair |
GND |
Ground |
71 |
HSOn(13) |
GND |
Ground |
72 |
GND |
Ground |
HSIp(13) |
Receiver Lane 13, Differential pair |
73 |
GND |
Ground |
HSIn(13) |
74 |
HSOp(14) |
Transmitter Lane 14, Differential pair |
GND |
Ground |
75 |
HSOn(14) |
GND |
Ground |
76 |
GND |
Ground |
HSIp(14) |
Receiver Lane 14, Differential pair |
77 |
GND |
Ground |
HSIn(14) |
78 |
HSOp(15) |
Transmitter Lane 15, Differential pair |
GND |
Ground |
79 |
HSOn(15) |
GND |
Ground |
80 |
GND |
Ground |
HSIp(15) |
Receiver Lane 15, Differential pair |
81 |
PRSNT#2 |
Hot plug present detect |
HSIn(15) |
82 |
RSVD#2 |
Hot Plug Detect |
GND |
Ground |
| |