pi2eqx5804d Pericom Semiconductor Corporation, pi2eqx5804d Datasheet - Page 7

• Manufacturer Part Number: pi2eqx5804d
• Description: 5.0gbps 4-lane Pcie? 2.0 Redrivertm With Equalization & Emphasis
• 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 PI2EQX5804D 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
to low, then the Receiver Detect operation for that group of channel is disabled, and those channels go directly to 50-Ohm input ter-
mination to ground and 50-Ohm output termination to V
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 is begins the differential channel pins are enabled with a 2K-Ohm pullup to V
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 output signals RX50_A and RX50_B represent the receiver detect result for their specific channels.
The I/O Operation table summaries the relationships and operation of receiver detect and other signals involved with I/O control.
I/O Operation Control
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PD# RXD_x
0
1
1
1
1
1
1
1
Control Inputs
X
0
0
0
1
1
1
1
RESET#
X
0
1
1
0
1
1
1
RX50
X
X
X
X
X
0
1
1
Detection
States
SIG_x
X
X
0
1
X
X
0
1
5.0Gbps 4-Lane PCIe® 2.0 ReDriver™ with Equalization & Emphasis
Input Termination
Hi-Z
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
DD
(for a valid differential channel input level) or to 2K-Ohm (if the signal
7
10-0170
2K-Ohm pull-up
2K-Ohm pull-up
Output Termination
Hi-Z
2K-Ohm pull-up
50-Ohm pull-up
2K-Ohm pull-up
2K-Ohm pull-up
50-Ohm pull-up
2
C programming. When RXD_A or RXD_B is set
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Mode
Full IC power down, all channels
disabled
Channel disabled, output pulls to
V
Channel enabled, no input signal,
output pulls to V
detect disabled
Channel enabled, valid input
signal detected, output driving.
Receiver detect disabled.
Channel disabled. Receiver detect
reset.
Channel disabled, output pulls to
V
receiver detected.
Channel inactive, output pulls
to V
receiver detected. No input signal
Channel active, valid input signal
detected, output driving. Receiver
detect enabled, load detected.
DD
DD
DD
. Receiver detect reset
. Receiver detect enabled, no
. Receiver detect enabled,
PI2EQX5804D
DD.
A 50-Ohm Receiver
DD
P-0.1
. Receiver
05/28/10