Texas Instruments XIO2001IZWS

Overview

XIO2001IZWS from Texas Instruments is a single-function PCI Express to PCI bus translation bridge compliant with PCI Express Base Specification 2.0 and PCI Local Bus Specification 2.3. It provides full ×1 PCIe throughput (250 MB/s bidirectional), supports 32-bit/66-MHz PCI bus operation, and integrates internal arbitration for up to six external PCI masters. It is deployed in enterprise server add-in cards requiring legacy PCI device integration via modern PCIe host interfaces.

For engineers reviewing the XIO2001IZWS datasheet, XIO2001IZWS pinout, XIO2001IZWS application, or XIO2001IZWS equivalent, key selection criteria include PCIe-to-PCI latency behavior, dual-voltage (3.3 V/5.0 V) PCI bus tolerance, ECRC-enabled error reporting, and support for L0s/L1 active-state power management - all critical for reliable bridging in data center and industrial control systems.

Technical Context

The XIO2001IZWS implements a robust pipeline architecture to minimize transaction latency between its ×1 PCIe upstream port and downstream 32-bit PCI bus. It handles up to eight posted and four non-posted downstream transactions simultaneously, and six posted and four non-posted upstream transactions - enabling efficient burst transfers across protocol boundaries.

It supports both 100-MHz differential and 125-MHz single-ended reference clocks, with optional spread-spectrum clocking. The device includes advanced power management features: CLKREQ-driven clock gating, WAKE signal for link reactivation, and integrated AUX power switch that drains VAUX only when main power is off - reducing standby current in always-on systems.

Key Specifications

Pinout & Package

The XIO2001IZWS is packaged in a 169-ball ZWS nFBGA (12.00 mm × 12.00 mm), RoHS-compliant, with exposed thermal pad for enhanced heat dissipation. Pin functions are defined per TI SCPS212J Rev J (Jan 2021), with ball mapping validated for ZWS package.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PEX8112-AA50BCF and PI7C9X20404BQF, the XIO2001IZWS uniquely balances compact nFBGA packaging, native 3.3-V/5.0-V PCI bus support, and integrated VAUX power switching - making it optimal for space-constrained, mixed-voltage, low-standby-power embedded bridging applications.

Availability

XIO2001IZWS is available at Aetrix Electronics and suitable for enterprise server add-in cards, industrial control backplanes, retail payment terminal expansions, and data center storage interposer boards requiring stable component supply across extended product lifecycles.

Supply support for XIO2001IZWS 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 focused on analog, embedded processing, and connectivity technologies, serving industrial, automotive, and communications markets with high-reliability components.

The XIO2001IZWS belongs to TI's PCI Express bridge product line, designed specifically to extend the usability of legacy PCI peripherals in modern PCIe-based systems - targeting enterprise infrastructure, industrial automation, and secure transaction platforms.

FAQ

What is the primary function of the XIO2001IZWS?

The XIO2001IZWS is a single-function PCI Express to PCI bus translation bridge. Its core function is to enable communication between a ×1 PCIe host interface and a legacy 32-bit PCI bus, supporting full 66-MHz operation and dual-voltage (3.3 V/5.0 V) PCI signaling. It complies with PCI Express Base Specification 2.0 and PCI Local Bus Specification 2.3, and is implemented in a 169-ball ZWS nFBGA package. The XIO2001IZWS is used where backward compatibility with existing PCI peripherals is required in PCIe-based systems.

Does the XIO2001IZWS support 5.0-V PCI bus operation?

Yes, the XIO2001IZWS supports 5.0-V PCI bus operation at 25 MHz or 33 MHz, using external 1-kΩ resistors connected to the PCIR pins to set the clamp rail voltage. This capability allows direct integration into legacy 5-V PCI slots without level-shifting circuitry. The XIO2001IZWS also supports 3.3-V PCI operation at up to 66 MHz. Both modes are selectable via hardware configuration, and the device maintains full compliance with PCI Local Bus Specification 2.3 in either configuration.

What reference clock options does the XIO2001IZWS accept?

The XIO2001IZWS accepts two reference clock configurations: a 100-MHz differential common-reference clock applied to REFCLK+ and REFCLK−, or a 125-MHz single-ended clock applied to REFCLK+. The selection is controlled by the REFCLK125_SEL pin. Spread-spectrum clocking is supported in both modes. The XIO2001IZWS uses this reference clock for PCIe PHY timing and internal PLL generation, and its stability directly affects PCIe link reliability and jitter performance.

How does the XIO2001IZWS manage power in low-activity states?

The XIO2001IZWS implements multiple power-saving mechanisms: Active-State Power Management (ASPM) with L0s and L1 states, CLKREQ-driven clock gating, and an integrated AUX power switch that drains VAUX only when main power is off. These features reduce dynamic and static power consumption during idle periods without disrupting PCIe link integrity. The XIO2001IZWS also supports D1, D2, D3hot, and D3cold device power states per PCI Express specification.

Can the XIO2001IZWS be used with an external PCI arbiter?

Yes, the XIO2001IZWS supports both internal and external PCI arbitration. When EXT_ARB_EN is asserted high, the device disables its internal arbiter and uses external GNT/REQ signals for bus control. The internal arbiter supports up to six external PCI masters with configurable 2-level prioritization. This flexibility allows the XIO2001IZWS to adapt to diverse system architectures - from simple single-master designs to complex multi-peripheral backplanes - without requiring changes to the XIO2001IZWS configuration.