Version 1.2 2009 Features PEX 8604 General Features o 4-lane PCI Express switch - Integrated 5.0 GT/s SerDes o Up to 4 configurable ports o 15 x 15mm2, 196-ball PBGA o Typical Power: 1.29 Watts PEX 8604 Key Features o Standards Compliant - PCI Express Base Specification r2.0 (Backwards compatible with PCIe r1.0a/1.1) - PCI Power Management Spec r1.2 - Microsoft Vista Compliant - Supports Access Control Services - Dynamic link-width control o High Performance - Non-blocking internal architecture - Full line rate on all ports - Cut-Thru latency: 190ns - 2KB max payload size - Read Pacing (intelligent bandwidth allocation) - Dual Cast o Dual-Host & Fail-Over Support - Configurable Non-Transparent port (NTB) - Moveable upstream port - Crosslink port capability on all ports o Flexible Configuration - 4 flexible & configurable ports (x1 or x2) - Configurable with strapping pins, EEPROM, I2C, or Host software - Lane and polarity reversal o PCI Express Power Management - Link power management states: L0, L0s, L1, L2/L3 Ready, and L3 - Device states: D0 and D3hot o Spread Spectrum Clock Isolation - Dual clock domain o Quality of Service (QoS) - Two Virtual Channels (VC) per port - Eight Traffic Classes per port - Weighted Round-Robin Port & VC Arbitration o Reliability, Availability, Serviceability - All ports Hot-Plug capable thru I2C (Hot-Plug Controller on every port) - ECRC & Poison bit support - Data path protection - Memory (RAM) error correction - Advanced Error Reporting support - Port Status bits and GPIO available - Per port error diagnostics - Performance monitoring (per port payload & header counters) - JTAG AC/DC boundary scan - Fatal Error (FATAL_ERR#) output signal - INTA# output signal PEX 8604 Flexible & Versatile 4-lane 4-port PCI Express® Switch The ExpressLane™ PEX 8604 device offers PCI Express switching capability enabling users to add scalable high bandwidth non-blocking interconnection to a wide variety of applications including control plane applications, consumer applications and embedded systems. The PEX 8604 is well suited for fan-out, peer-to-peer, and intelligent I/O module applications. Low Packet Latency & High Performance The PEX 8604 architecture supports packet cut-thru with a maximum latency of 190ns in x1 to x1 configuration. This, combined with low power consumption and non-blocking internal switch architecture, provides full line rate on all ports for lowpower applications such as consumer and embedded. The low latency enables applications to achieve high throughput and performance. In addition to low latency, the device supports a max payload size of 2048 bytes, enabling the user to achieve even higher throughout. Data Integrity The PEX 8604 provides end-to-end CRC protection (ECRC) and Poison bit support to enable designs that require guaranteed error-free packets. PLX also supports data path parity and memory (RAM) error correction as packets pass through the switch. Dual-Host and Fail-Over Support The PEX 8604 supports full non-transparent bridging (NTB) functionality to allow implementation of multi-host systems and intelligent I/O modules in applications which require redundancy support such as select embedded applications. Non-transparent bridges allow systems to isolate host memory domains by presenting the processor subsystem as an endpoint rather than another memory system. Base address registers are used to translate addresses, doorbell registers are used to send interrupts between the address domains, and scratchpad registers are accessible from both address domains to allow inter-processor communication. Interoperability The PEX 8604 is designed to be fully compliant with the PCI Express Base Specification r2.0 and is backwards compatible to PCI Express Base Specification r1.1 and r1.0a. Additionally each port supports auto-negotiation and polarity reversal. Furthermore, the PEX 8604 is designed for Microsoft Vista compliance. All PLX switches undergo thorough interoperability testing in PLX’s Interoperability Lab and compliance testing at the PCI-SIG plug-fest to ensure compatibility with PCI Express devices in the market. Device Operation Configuration Flexibility The PEX 8604 provides several ways to configure its operations. The device can be configured through strapping pins, I2C interface, CPU configuration cycles and/or an optional serial EEPROM. This allows for easy debug during the development phase and functional monitoring during the operation phase. Flexible Port Configurations The PEX 8604 flexible architecture supports a number of port configurations as required by the target applications as shown in figure 1 below. off, low, typical, and high. The SerDes block also supports loop-back modes and advanced reporting of error conditions, which enables efficient debug and management of the entire system. Port and Virtual Channel (VC) Arbitration The PEX 8604 switch supports hardware fixed and Weighted Round-Robin Ingress Port Arbitration. This allows fine tuning of Quality of Service and efficient use of packet buffers for better system performance. The PEX 8604 also supports WRR VC arbitration scheme between the two virtual channels. Applications Suitable for fan-out, control plane applications, embedded systems as well as intelligent I/O applications, PEX 8604 can be configured for a wide variety of form factors and applications. Figure 1. Port Configurations Hot-Plug for High Availability Hot-Plug capability allows users to replace hardware modules and perform maintenance without powering down the system. The PEX 8604 Hot-Plug capability feature makes it suitable for High Availability (HA) applications. If the PEX 8604 is used in an application where one or more of its downstream ports connect to PCI Express slots, each port’s Hot-Plug Controller can be used to manage the Hot-Plug event of its associated slot. Every port on the PEX 8604 is equipped with a Hot-Plug control/status register to support Hot-Plug capability through external logic via the I2C interface. Fan-Out The PEX 8604 switch, with its flexible configurations, allows user specific tuning to a variety of host-centric as well as peer-to-peer applications. Dual Cast The PEX 8604 supports Dual Cast, a feature which allows for the copying of data (e.g. packets) from one ingress port to two egress ports allowing for higher performance in storage, security, and mirroring applications. Read Pacing The Read Pacing feature allows users to throttle the amount of read requests being made by downstream devices. In the case where a downstream device requests several long reads backto-back, the Root Complex gets tied up in serving this downstream port. If this port has a narrow link and is therefore slow in receiving these read packets from the Root Complex, then other downstream ports may become starved – thus, impacting performance. The Read Pacing feature enhances performances by allowing for the adequate servicing of all downstream devices by intelligent handling of read requests. SerDes Power and Signal Management The PEX 8604 provides low power capability that is fully compliant with the PCI Express power management specification. In addition, the SerDes physical links can be turned off when unused for even lower power. The PEX 8604 supports software control of the SerDes outputs to allow optimization of power and signal strength in a system. The PLX SerDes implementation supports four levels of power – Figure 2. Fan-in/out Usage Figure 2 shows a typical fan-out design, where the processor provides a PCI Express link that needs to be fanned into a larger number of smaller ports for a variety of I/O functions, each with different bandwidth requirements. In this example, the PEX 8604 would typically have a 1-lane upstream port, and three downstream ports. The downstream ports provide x1 PCI Express connectivity to the endpoints. With its four ports, the PEX 8604 can provide fan-out connectivity to up to three PCI Express devices. The figure also shows how some of the ports can be bridged to provide PCI slots through the use of the PEX 8112 PCIe bridging devices. Consumer Applications With its small footprint, the PEX 8604 is ideal for consumer applications. Figure 3 shows an example for a set top box. The PEX8604 connects to legacy devices using a PEX85112 (PCIe to PCI bridge). The four ports in the PEX8604 provide connectivity between the processor to up to three peripherals each via an x1 connection. This usage model provides connectivity within a set top box between the control processor and the various endpoints. Intelligent Adapter Card The PEX 8604 supports the non-transparency feature. Figure 6 illustrates a host system using an intelligent adapter card. Figure 3. Set Top Box Mobile Wireless Adaptor PEX 8604 devices can be used in applications where low power consumption is of importance as is the case in mobile applications. An example of a mobile wireless adapter card is shown in Figure 4. Figure 6. Intelligent Adapter Usage In this figure, the CPU on the adapter card is isolated from the host CPU. The PEX 8604 non-transparent port allows the two CPUs to be isolated but communicate with each other through various registers that are designed in the PEX 8604 for that purpose. The host CPU can dynamically re-assign both the upstream port and the non-transparent port of PEX 8604 allowing the system to be reconfigured. Active-Standby Failover Model The PEX 8604 supports applications requiring dual host, host failover applications through the non-transparency (NTB) feature. Figure 7 illustrates a dual host system with an active and standby processor configuration. Figure 4. Mobile Wireless Adaptor Embedded Mezzanine Module The PEX 8604 is well suited for mezzanine module applications. Figure 5 shows that the mezzanine card has a local processor and a local PCIe hierarchy with the PEX8604 and multiple endpoints. Additionally, the non-transparent port in the PEX8604 allows the mezzanine to interface with the main CPU in the Baseboard as well as other mezzanine modules. Figure 5. PCI Express Mezzanine Module The redundancy of the host and the fabric can be achieved through many possible configurations using NTB function of PEX 8604. In the configuration shown below Processor A is the primary active host of the PCI Express system. Processor B acts as the backup Host. In the case of a failure on Processor A, application software is instructed to migrate the PCI Express system to Processor B. Consequently, Processor B becomes the active host and Processor A can be replaced as the backup Host. Figure 7. Active-Standby Control Plane Software Usage Model Interrupt Sources/Events From a system model viewpoint, each PCI Express port is a virtual PCI to PCI bridge device and has its own set of PCI Express configuration registers. It is through the upstream port that the BIOS or host can configure the other ports using standard PCI enumeration. The virtual PCI-to-PCI bridges within the PEX 8604 are compliant to the PCI and PCI Express system models. The Configuration Space Registers (CSRs) in a virtual primary/secondary PCI-to-PCI bridge are accessible by type 0 configuration cycles through the virtual primary bus interface (matching bus number, device number, and function number). The PEX 8604 supports the INTx interrupt message type (compatible with PCI 2.3 Interrupt signals) or Message Signaled Interrupts (MSI) when enabled. Interrupts/messages are generated by PEX 8604 for Hot-Plug events, doorbell interrupts, baseline error reporting, and advanced error reporting. Development Tools RDK PLX offers hardware and software tools to enable rapid customer design activity. These tools consist of a PEX 8604 Rapid Development Kit (RDK), hardware documentation, and a Software Development Kit (also available at www.plxtech.com/sdk). The PEX 8604RDK is a hardware module containing the PEX 8604 which plugs right into your system (Figure 8). The PEX 8604RDK hardware module can be installed in a motherboard, used as a riser card, or configured as a bench-top board. The PEX 8604RDK can be used to test and validate customer software. Additionally, it can be used as an evaluation vehicle for PEX 8604 features and benefits. SDK The SDK tool set includes: - Linux & Windows drivers - C/C++ Source code, Objects, libraries - User’s Guides & Application examples Windows/Linux Apps User Space PEX API Kernel Space Hardware PCIe Driver NT PnP Driver PCI Express Interface Figure 8. PEX 8604RDK Product Ordering Information PLX Technology, Inc. 870 W. Maude Ave. Sunnyvale, CA 94085 USA www.plxtech.com Part Number Description PEX8604-BA50BC PEX8604-BA50BC G PEX 8604BA-AIC1U1D RDK 4 Lane, 4 Port PCIe Switch, 196-ball PBGA 15x15mm2 pkg 4 Lane, 4 Port PCIe Switch, 196-ball PBGA 15x15mm2 pkg, Pb-free PEX 8604 Rapid Development Kit with 4-ports Please visit the PLX Web site at http://www.plxtech.com for sampling. © 2009 by PLX Technology, Inc. All rights reserved. PLX and the PLX logo are registered trademarks of PLX Technology, Inc. ExpressLane is a trademark of PLX Technology, Inc., which may be registered in some jurisdiction. All other product names that appear in this material are for identification purposes only and are acknowledged to be trademarks or registered trademarks of their respective companies. Information supplied by PLX is believed to be accurate and reliable, but PLX Technology, Inc. assumes no responsibility for any errors that may appear in this material. PLX Technology, Inc. reserves the right, without notice, to make changes in product design or specification. PEX 8604-SIL-PB-1.2 5/09