8-Lane 5-Port

PCI Express® Switch

®

89HPES8T5A

Data Sheet

Device Overview

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The 89HPES8T5A is a member of IDT’s PRECISE™ family of PCI

Express switching solutions. The PES8T5A is an 8-lane, 5-port periph-

eral chip that performs PCI Express Base switching. It provides connec-

tivity and switching functions between a PCI Express upstream port and

up to four downstream ports and supports switching between down-

stream ports.

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Features

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High Performance PCI Express Switch

– Eight 2.5Gbps PCI Express lanes

– Five switch ports

– Upstream port is x4

– Downstream ports are x1

– Low-latency cut-through switch architecture

– Support for Max Payload Sizes up to 256 bytes

– One virtual channel

– Eight traffic classes

– PCI Express Base Specification Revision 1.1 compliant

Flexible Architecture with Numerous Configuration Options

– Automatic lane reversal on all ports

– Automatic polarity inversion on all lanes

– Ability to load device configuration from serial EEPROM

Legacy Support

– PCI compatible INTx emulation

– Bus locking

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Highly Integrated Solution

– Requires no external components

– Incorporates on-chip internal memory for packet buffering and

queueing

– Integrates eight 2.5 Gbps embedded SerDes with 8B/10B

encoder/decoder (no separate transceivers needed)

Reliability, Availability, and Serviceability (RAS) Features

– Internal end-to-end parity protection on all TLPs ensures data

integrity even in systems that do not implement end-to-end

CRC (ECRC)

– Supports ECRC and Advanced Error Reporting

– Supports PCI Express Native Hot-Plug, Hot-Swap capable I/O

– Compatible with Hot-Plug I/O expanders used on PC mother-

boards

Power Management

– Utilizes advanced low-power design techniques to achieve low

typical power consumption

– Supports PCI Power Management Interface specification (PCI-

PM 1.2)

– Unused SerDes are disabled.

– Supports Advanced Configuration and Power Interface Speci-

fication, Revision 2.0 (ACPI) supporting active link state

Testability and Debug Features

– Built in Pseudo-Random Bit Stream (PRBS) generator

– Numerous SerDes test modes

– Ability to read and write any internal register via the SMBus

– Ability to bypass link training and force any link into any mode

– Provides statistics and performance counters

Block Diagram

5-Port Switch Core / 8 PCI Express Lanes

Frame Buffer

Route Table

Port

Arbitration

Scheduler

Transaction Layer

Data Link Layer

Transaction Layer

Data Link Layer

Transaction Layer

Data Link Layer

Transaction Layer

Data Link Layer

Transaction Layer

Data Link Layer

Mux / Demux

Phy

Logical

Layer

Mux / Demux

Phy

Logical

Layer

Mux / Demux

Phy

Logical

Layer

Mux / Demux

Phy

Logical

Layer

Mux / Demux

Phy

Logical

Layer

SerDes

(Port 0)

(Port 2)

(Port 3)

Figure 1 Internal Block Diagram

(Port 4)

(Port 5)

IDT and the IDT logo are registered trademarks of Integrated Device Technology, Inc.

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

2014 Integrated Device Technology, Inc.

June 18, 2014

IDT 89HPES8T5A Data Sheet

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11 General Purpose Input/Output Pins

– Each pin may be individually configured as an input or output

– Each pin may be individually configured as an interrupt input

– Some pins have selectable alternate functions

Packaged in a 15mm x 15mm 196-ball BGA with 1mm ball spacing

Product Description

Utilizing standard PCI Express interconnect, the PES8T5A provides the most efficient I/O connectivity solution for applications requiring high

throughput, low latency, and simple board layout with a minimum number of board layers. It provides 3 GBps (24 Gbps) of aggregated, full-duplex

switching capacity through 6 integrated serial lanes, using proven and robust IDT technology. Each lane provides 2.5 Gbps of bandwidth in both direc-

tions and is fully compliant with PCI Express Base specification revision 1.1.

The PES8T5A is based on a flexible and efficient layered architecture. The PCI Express layer consists of SerDes, Physical, Data Link and Trans-

action layers in compliance with PCI Express Base specification Revision 1.1. The PES8T5A can operate either as a store and forward or cut-through

switch and is designed to switch memory and I/O transactions. It supports eight Traffic Classes (TCs) and one Virtual Channel (VC) with sophisticated

resource management to allow efficient switching for applications requiring additional narrow port connectivity.

Processor

North

Bridge

Memory

South

Bridge

x4

PES8T5A

x1

GE

LOM

x1

GE

LOM

x1

GE

x1

1394

Figure 2 I/O Expansion Application

SMBus Interface

The PES8T5A contains two SMBus interfaces. The slave interface provides full access to the configuration registers in the PES8T5A, allowing

every configuration register in the device to be read or written by an external agent. The master interface allows the default configuration register

values of the PES8T5A to be overridden following a reset with values programmed in an external serial EEPROM. The master interface is also used

by an external Hot-Plug I/O expander.

Six pins make up each of the two SMBus interfaces. These pins consist of an SMBus clock pin, an SMBus data pin, and 4 SMBus address pins. In

the slave interface, these address pins allow the SMBus address to which the device responds to be configured. In the master interface, these

address pins allow the SMBus address of the serial configuration EEPROM from which data is loaded to be configured. The SMBus address is set up

on negation of PERSTN by sampling the corresponding address pins. When the pins are sampled, the resulting address is assigned as shown in

Table 1.

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June 18, 2014

IDT 89HPES8T5A Data Sheet

Bit

1

2

3

4

5

6

7

Slave

SMBus

Address

SSMBADDR[1]

SSMBADDR[2]

SSMBADDR[3]

0

SSMBADDR[5]

1

Master

SMBus

Address

MSMBADDR[1]

MSMBADDR[2]

MSMBADDR[3]

MSMBADDR[4]

1

0

1

Table 1 Master and Slave SMBus Address Assignment

As shown in

Figure 3,

the master and slave SMBuses may be used in a unified or split configuration. In the unified configuration, shown in

Figure

3(a),

the master and slave SMBuses are tied together and the PES8T5A acts both as a SMBus master as well as a SMBus slave on this bus. This

requires that the SMBus master or processor that has access to PES8T5A registers supports SMBus arbitration. In some systems, this SMBus master

interface may be implemented using general purpose I/O pins on a processor or micro controller, and may not support SMBus arbitration. To support

these systems, the PES8T5A may be configured to operate in a split configuration as shown in

Figure 3(b).

In the split configuration, the master and slave SMBuses operate as two independent buses and thus multi-master arbitration is never required.

The PES8T5A supports reading and writing of the serial EEPROM on the master SMBus via the slave SMBus, allowing in system programming of the

serial EEPROM.

PES8T5A

Processor

SMBus

Master

Serial

EEPROM

...

Other

SMBus

Devices

PES8T5A

Processor

SMBus

Master

...

Other

SMBus

Devices

SSMBCLK

SSMBDAT

MSMBCLK

MSMBDAT

SSMBCLK

SSMBDAT

MSMBCLK

MSMBDAT

Serial

EEPROM

(a) Unified Configuration and Management Bus

(b) Split Configuration and Management Buses

Figure 3 SMBus Interface Configuration Examples

Hot-Plug Interface

The PES8T5A supports PCI Express Hot-Plug on each downstream port. To reduce the number of pins required on the device, the PES8T5A

utilizes an external I/O expander, such as that used on PC motherboards, connected to the SMBus master interface. Following reset and configura-

tion, whenever the state of a Hot-Plug output needs to be modified, the PES8T5A generates an SMBus transaction to the I/O expander with the new

value of all of the outputs. Whenever a Hot-Plug input changes, the I/O expander generates an interrupt which is received on the IOEXPINTN input pin

(alternate function of GPIO) of the PES8T5A. In response to an I/O expander interrupt, the PES8T5A generates an SMBus transaction to read the

state of all of the Hot-Plug inputs from the I/O expander.

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June 18, 2014

IDT 89HPES8T5A Data Sheet

General Purpose Input/Output

The PES8T5A provides 11 General Purpose Input/Output (GPIO) pins that may be used by the system designer as bit I/O ports. Each GPIO pin

may be configured independently as an input or output through software control. Some GPIO pins are shared with other on-chip functions. These

alternate functions may be enabled via software, SMBus slave interface, or serial configuration EEPROM.

Pin Description

The following tables lists the functions of the pins provided on the PES8T5A. Some of the functions listed may be multiplexed onto the same pin.

The active polarity of a signal is defined using a suffix. Signals ending with an “N” are defined as being active, or asserted, when at a logic zero (low)

level. All other signals (including clocks, buses, and select lines) will be interpreted as being active, or asserted, when at a logic one (high) level.

Signal

PE0RP[3:0]

PE0RN[3:0]

PE0TP[3:0]

PE0TN[3:0]

PE2RP[0]

PE2RN[0]

PE2TP[0]

PE2TN[0]

PE3RP[0]

PE3RN[0]

PE3TP[0]

PE3TN[0]

PE4RP[0]

PE4RN[0]

PE4TP[0]

PE4TN[0]

PE5RP[0]

PE5RN[0]

PE5TP[0]

PE5TN[0]

PEREFCLKP

PEREFCLKN

Type

I

O

I

O

I

O

I

O

I

O

I

Name/Description

PCI Express Port 0 Serial Data Receive.

Differential PCI Express receive

pairs for port 0.

PCI Express Port 0 Serial Data Transmit.

Differential PCI Express trans-

mit pairs for port 0.

PCI Express Port 2 Serial Data Receive.

Differential PCI Express receive

pair for port 2.

PCI Express Port 2 Serial Data Transmit.

Differential PCI Express trans-

mit pair for port 2.

PCI Express Port 3 Serial Data Receive.

Differential PCI Express receive

pair for port 3.

PCI Express Port 3 Serial Data Transmit.

Differential PCI Express trans-

mit pair for port 3.

PCI Express Port 4 Serial Data Receive.

Differential PCI Express receive

pair for port 4.

PCI Express Port 4 Serial Data Transmit.

Differential PCI Express trans-

mit pair for port 4.

PCI Express Port 5 Serial Data Receive.

Differential PCI Express receive

pair for port 5.

PCI Express Port 5 Serial Data Transmit.

Differential PCI Express trans-

mit pair for port 5.

PCI Express Reference Clock.

Differential reference clock pair input. This

clock is used as the reference clock by on-chip PLLs to generate the clocks

required for the system logic and on-chip SerDes. The frequency of the dif-

ferential reference clock is determined by the REFCLKM signal.

PCI Express Reference Clock Mode Select.

This signal selects the fre-

quency of the reference clock input.

0x0 - 100 MHz

0x1 - 125 MHz

Table 2 PCI Express Interface Pins

REFCLKM

I

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June 18, 2014

IDT 89HPES8T5A Data Sheet

Signal

MSMBADDR[4:1]

MSMBCLK

MSMBDAT

SSMBADDR[5,3:1]

SSMBCLK

SSMBDAT

Type

I

I/O

I

I/O

Name/Description

Master SMBus Address.

These pins determine the SMBus address of the

serial EEPROM from which configuration information is loaded.

Master SMBus Clock.

This bidirectional signal is used to synchronize

transfers on the master SMBus.

Master SMBus Data.

This bidirectional signal is used for data on the mas-

ter SMBus.

Slave SMBus Address.

These pins determine the SMBus address to

which the slave SMBus interface responds.

Slave SMBus Clock.

This bidirectional signal is used to synchronize trans-

fers on the slave SMBus.

Slave SMBus Data.

This bidirectional signal is used for data on the slave

SMBus.

Table 3 SMBus Interface Pins

Signal

GPIO[0]

Type

I/O

Name/Description

General Purpose I/O.