pi2eqx5864d Pericom Semiconductor Corporation, pi2eqx5864d Datasheet - Page 6

• Manufacturer Part Number: pi2eqx5864d
• Description: 5.0gbps 4-lane Pcie? 2.0 Redrivertm With Equalization, Emphasis, & I2c Control
• Manufacturer: Pericom Semiconductor Corporation

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 PI2EQX5864D to configure itself properly de-
pending 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 I
low, the Receiver Detect operation for that group of channels is disabled, and those channels go directly to 50-Ohm input termina-
tion 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).
The RESET# input is used to reset the receiver detect state machine to its initial state. The start of the receiver detect cycle starts
when RESET# transitions from low to high.
When a Receiver Detect cycle begins the differential channel pins are enabled with a 2K-Ohm pull-up to V DD . A 50-Ohm Receiver
termination will change the pin level. This pin level is evaluated after a fixed time-out, and the channel is then set into the proper
operating state. The register bits RX50_Ax and RX50_Bx represent the receiver detect result for their specific channels.
The I/O operation table summarizes the relationships and operation of receiver detect and other signals involved with I/O control.
I/O Operation Control
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0
0
0
1
1
1
1
Control Inputs
RXD_x
RESET#
0
1
1
0
1
1
1
X
X
X
X
0
1
1
Detection
States
RX50
SIG_x
X
0
1
X
X
0
1
Hi-Z
50-Ohm pull-down
50-Ohm pull-down
Hi-Z
Hi-Z
50-Ohm pull-down
50-Ohm pull-down
Data Channel I/O
Input
Termination
10-0172
5.0Gbps 4-Lane PCIe® 2.0 ReDriver™ with Equalization
2K-Ohm pull-up
2K-Ohm pull-up
50-Ohm pull-up
2K-Ohm pull-up
2K-Ohm pull-up
2K-Ohm pull-up
50-Ohm pull-up
Output
Termination
6
2
C programming. When RXD_A or RXD_B is set to
Channel disabled, output pulls to V DD .
Receiver detect reset
Channel enabled, no input signal, output
pulls to V DD . Receiver detect disabled
Channel enabled, valid input signal detected,
output driving. Receiver detect disabled.
Channel disabled. Receiver detect reset.
Channel disabled, output pulls to V DD . Re-
ceiver detect enabled, no receiver detected.
Channel inactive, output pulls to V DD . Re-
ceiver detect enabled, receiver detected. No
input signal
Channel active, valid input signal detected,
output driving. Receiver detect enabled, load
detected.
Mode
www.pericom.com
PI2EQX5864D
PS 0.1
06/04/10