Texas Instruments XIO2000AZAY

Overview

XIO2000AZAY from Texas Instruments is a PCI Express to PCI bus translation bridge IC enabling legacy PCI peripherals to operate in PCIe-based host systems. It supports PCIe 1.0a (2.5 GT/s) upstream and 33 MHz 32-bit PCI bus downstream, features integrated configuration space translation, MSI message generation, and advanced error reporting. It is used in industrial control backplanes and embedded computing upgrades where PCIe host compatibility with existing PCI add-in cards is required.

For engineers reviewing the XIO2000AZAY datasheet, XIO2000AZAY pinout, XIO2000AZAY application, or XIO2000AZAY equivalent, this device is selected for PCIe-to-PCI protocol bridging, low-latency memory-mapped I/O translation, and support of isochronous PCI windows in real-time data acquisition systems.

Technical Context

The XIO2000AZAY implements a full-function bridge with dual-domain transaction layer logic: PCIe Transaction Layer handles TLP encoding/decoding, flow control, and AER, while the PCI domain manages configuration cycles, address/data multiplexing, and arbitration via 128-phase WRR scheduling. It supports Type 0 and Type 1 configuration transactions and translates PCI INTx signals into PCIe Message Signaled Interrupts.

Its power management includes PCIe L0s/L1 states and PCI D0–D3hot transitions, coordinated via PME forwarding and serial IRQ interface. The device integrates a two-wire serial-bus controller for EEPROM configuration storage and GPIOs for board-level control signaling, all managed through TI-proprietary register space mapped at fixed memory addresses.

Key Specifications

Pinout & Package

The XIO2000AZAY is housed in a 324-pin MicroStar BGA package (ZAY), with 15 mm × 15 mm body size, 1.0 mm ball pitch, and standard JEDEC MO-270AC footprint. Thermal pad on underside requires solder paste stencil design per TI SZZ-002B guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PCI Express-to-PCI bridge applications.

Compared with XIO2000AZAY, the PEX8112 offers higher PCI bandwidth but larger footprint and no native serial IRQ, while the PI7C9X20404 provides PCIe 2.0 headroom and compact packaging but omits isochronous windowing-critical for deterministic real-time data acquisition.

Availability

XIO2000AZAY is available at Aetrix Electronics and suitable for industrial backplane upgrades, medical imaging data acquisition, and avionics data concentrators requiring stable component supply throughout extended product lifecycles.

Supply support for XIO2000AZAY includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The XIO2000A family was designed specifically to extend the service life of PCI-based peripherals in PCIe infrastructure, targeting seamless interoperability, low-power operation, and robust error handling in mission-critical embedded systems.

FAQ

What is the primary function of the XIO2000AZAY?

The XIO2000AZAY is a PCI Express to PCI bus translation bridge IC that enables legacy PCI peripherals to interoperate with modern PCIe host systems. It performs full protocol translation-including configuration space mapping, interrupt conversion (INTx to MSI), and timing adaptation-while maintaining electrical and functional compliance with both PCIe 1.0a and PCI 2.2 specifications. Its design ensures deterministic latency and reliable data integrity in real-time embedded applications.

Does the XIO2000AZAY support hot-plug functionality?

The XIO2000AZAY supports PCIe hot-plug events via PERST# assertion and link retraining, and it detects PCI slot presence through GPIO monitoring and serial IRQ signaling. However, full hot-plug compliance-including surprise removal handling and software-initiated power cycling-requires system-level implementation of ACPI methods and BIOS/firmware coordination. The XIO2000AZAY provides the necessary hardware primitives but does not autonomously manage hot-plug state machines.

How does the XIO2000AZAY handle power management between PCIe and PCI domains?

The XIO2000AZAY implements coordinated power management by synchronizing PCIe L0s/L1 states with PCI D0–D3hot transitions. It forwards PME messages from PCI devices to the PCIe root complex and supports wake-on-serial-IRQ for low-power sleep exit. Power-up/down sequencing is strictly controlled via dedicated pins (CLKREQ#, PERST#) and internal state machines documented in Section 3.1 of the SCPS155C manual, ensuring safe voltage ramping and domain isolation.

Can the XIO2000AZAY be configured without external EEPROM?

Yes, the XIO2000AZAY can operate without external EEPROM by loading default configuration values from internal ROM during reset. However, persistent customization-including Vendor ID, Device ID, Subsystem ID, and GPIO initialization states-requires an external two-wire serial EEPROM connected to SCL/SDA pins. The XIO2000AZAY reads this EEPROM automatically at power-up unless overridden by host software writes to TI proprietary registers.

What is the maximum sustained data throughput achievable with the XIO2000AZAY?

The XIO2000AZAY delivers up to 132 MB/s sustained throughput on its 32-bit 33 MHz PCI bus, limited by PCI protocol overhead and arbitration latency-not by PCIe x1 link capacity (250 MB/s raw). Real-world throughput depends on burst length, master arbitration fairness, and upstream PCIe root complex efficiency. Measured benchmarks show 118–124 MB/s for 128-byte DMA bursts under balanced multi-master load, consistent with PCI 2.2 specification limits.