PI2EQX5804CNJE Datasheet, PDF (6/23 Pages) Pericom Semiconductor Corporation – 5.0Gbps 4-Lane PCIe® 2.0 ReDriver™ with Equalization & Emphasis

PI2EQX5804C
5.0Gbps 4-Lane PCIe® 2.0 ReDriver™ with
Equalization & Emphasis
Output Swing Control
S1_[A:B]
S0_[A:B]
0
0
0
1
1
0
1
1
Swing (Diff. VPP)
1V
0.5V
0.7V
0.9V
Emphasis settings are determined by the state of the DEx_y input pins and configuration registers, as shown in
the Output De-emphasis table below. De-Emphasis is selected as the default power-on mode in following the
PCI Express specification, but can be changed to Pre-emphasis via reprogramming the Loopback and Empha-
sis Control register using the I²C interface.
Output De-emphasis Adjustment
D2_[A:B]
D1_[A:B]
D0_[A:B]
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
De-emphasis
0dB
-2.5dB
-3.5dB
-4.5dB
-5.5dB
-6.5dB
-7.5dB
-8.5dB
Input Level Detect
An input level detect and output squelch function is provided on each channel to eliminate re-transmission of
input noise. A continuous signal level below the V_th- threshold causes the output driver to go to a high-impre-
dance state, so that both the positive and negative output signal are pulled to V_DD by the internal pull-up resis-
tors. This feature supports the L0s PCI Express Electrical Idle state.
Receiver Detect
Automatic Receiver Detection is a feature that can set the number of active channels. By sensing the presence of a load
device on the output, the channel can be automatically enabled for operation. This allows the PI2EQX5804C to config-
ure itself properly depending on the devices it is communicating with, whether it is a 4-lane, 3-lane, 2-lane or just 1-lane
device or adapter card.
Receiver Detect is enabled by the RXD_A, or RXD_B pins, or alternatively via I²C programming. When RXD_A or
RXD_B is set to low, then the Receiver Detect operation for that group of channel is disabled, and those channels go
directly to 50-Ohm input termination to ground and 50-Ohm output termination to V_DD (for a valid differential channel
input level) or to 2K-Ohm (if the signal level is less than the threshold level).
(Continued)
09-0001
6
PS8926B
06/08/09