8.2.1 PCIe x8 Lane Switching

The DS160PR412 and DS160PR421 and can be used in desktop motherboard applications to switch PCIe lanes

from a CPU in to one of the two PCIe CEM connectors. Figure 8-1 shows a simplified schematic for the

configuration. Two DS160PR412 demultiplex eight TX channels from CPU into one of the two PCIe slots. On the

other hand two DS160PR421 multiplex eight RX channels from one of the two PCIe slots to CPU.

Minimum

recommended

decoupling

EQ0

EQ1

Pin strap to

fine tune

EQ gain

settings

GND

GPIO mode

MODE

1 NŸ

RX_DET

GAIN

pin strap control

for DC gain

VREG1

0.1 F

Linear

Driver

RXnP

RXnN

CTLE

Linear

Driver

CPU

(root

complex)

DS160PR412

PCIe Redriver Demux

TXAnP

TXAnN

TXBnP

TXBnN

PD

SEL

VCC

0.1 F

(2x)

VCC

1 F

Minimum

recommended

decoupling

EQ0

EQ1

Pin strap to

fine tune

EQ gain

settings

GND

GPIO mode

MODE

1 NŸ

RX_DET

GAIN

Optional pin strap

control for DC gain

RXAnP

RXAnN

CTLE

Linear

Driver

PCIe

Slot

A

DS160PR421

PCIe Redriver Mux

TXnP

TXnN

PD

SEL

VCC

0.1 F

(2x)

VCC

1 F

CTLE

RXBnP

RXBnN

Mux selection

Mux selection

PCIe

Slot

B

8 TX Chan

8 RX Chan

X8 Slot

X16 Slot

8 Lanes

8 Lanes

8 Lanes

Two PR412

Two PR421

1 of 4

channels

1 of 4

channels

System Level

Power Control

System Level

Power Control

VREG2

0.1 F

VREG1

0.1 F

VREG2

0.1 F

Float

Float

Figure 8-1. Simplified Schematic for PCIe Lane Switching for PC Desktop Application

www.ti.com

DS160PR412

SNLS685 – DECEMBER 2020

Copyright © 2020 Texas Instruments Incorporated

Submit Document Feedback

19

Product Folder Links: DS160PR412