Texas Instruments PCI2250PCM

Overview

PCI2250PCM from Texas Instruments is a PCI-to-PCI bridge IC enabling hierarchical expansion of 33 MHz PCI buses in embedded and industrial systems. It supports concurrent burst-mode transactions across two independent 32-bit PCI interfaces, implements two-tier arbitration for up to four secondary bus masters, and delivers five programmable secondary clock outputs. It is used in compact-PCI hot-swap systems requiring electrical isolation and power-managed bus segmentation.

For engineers reviewing the PCI2250PCM datasheet, PCI2250PCM pinout, PCI2250PCM application, or PCI2250PCM equivalent, key selection criteria include subtractive/positive decode configurability, CLKRUN support for mobile docking, CPCI hot-swap compliance, and dual-bus latency predictability per PCI Local Bus Specification Rev 2.2.

Technical Context

The PCI2250PCM implements a fully compliant PCI-to-PCI Bridge Architecture Specification Rev 1.1 controller with dedicated primary and secondary interface logic. Its internal pipeline architecture enables simultaneous read/write buffering in both directions, and its extension window registers support programmable address decoding for serial/parallel port I/O and VGA palette memory access.

It features integrated power management per PCI Power Management Interface Spec Rev 1.0/1.1, including CLKRUN bridging and low-power state behavior coordination. Secondary bus arbitration is configurable as either internal two-tier (for ≤4 masters) or external via GNT/REQ signals, and error handling includes posted write timeout, SERR propagation, and parity error reporting on address/data phases.

Key Specifications

Pinout & Package

PCI2250PCM is packaged in a 160-pin plastic quad flat pack (PQFP), thermally optimized for industrial PCB layouts with exposed thermal pad (VCCP pins at terminals 58, 73, 119).

Key Features

Applications

Equivalent & Alternatives

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

Compared with PLX PCI9052 and Intel 21150, the PCI2250PCM uniquely integrates compact-PCI hot-swap control logic, five secondary clock outputs, and CLKRUN bridging-making it irreplaceable in ruggedized, field-upgradable embedded platforms requiring deterministic latency and zero-downtime maintenance.

Availability

PCI2250PCM is available at Aetrix Electronics and suitable for compact-PCI hot-swap systems, industrial rack-mount controllers, and mobile docking stations requiring stable component supply across extended product lifecycles.

Supply support for PCI2250PCM 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 company specializing in analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The PCI2250PCM belongs to TI's PCI Bridge product line, designed specifically for hierarchical bus expansion in electrically constrained, high-reliability embedded systems requiring hot-swap capability and low-power mobile operation.

FAQ

What is the maximum clock frequency supported by the PCI2250PCM?

The PCI2250PCM supports a maximum clock frequency of 33 MHz on both its primary and secondary PCI interfaces. This aligns with the PCI Local Bus Specification Revision 2.2 timing requirements and is validated across the full operating temperature range. The device does not support 66-MHz PCI modes, and all timing parameters-including setup/hold, skew, and jitter-are specified exclusively for 33-MHz operation in the SCPS051 data manual.

Does the PCI2250PCM support both positive and subtractive decoding on the primary interface?

Yes, the PCI2250PCM supports configurable decoding modes on the primary interface: either positive decoding (for specific memory/I/O address ranges) or subtractive decoding (to forward unmatched cycles to the secondary bus). This flexibility is implemented via the Primary Decode Control Register (Section 5.9 of SCPS051) and enables seamless integration into custom PCI architectures requiring legacy compatibility or hierarchical forwarding.

How many secondary PCI clock outputs does the PCI2250PCM provide, and what are their functions?

The PCI2250PCM provides five independent secondary PCI clock outputs: S_CLKOUT0 through S_CLKOUT4. Each is a buffered, 33-MHz output capable of driving one PCI slot or peripheral. These outputs support staggered clock enable/disable via the Secondary Clock Control Register (Section 5.19), allowing selective power-down of unused secondary slots to reduce system-level EMI and dynamic power consumption.

Is the PCI2250PCM compatible with Compact-PCI Hot Swap Specification Revision 1.0?

Yes, the PCI2250PCM is explicitly designed to comply with PICMG Compact-PCI Hot Swap Specification Revision 1.0. It includes dedicated pins (NO/HSLED and GOZ) and internal logic for hot-swap sequencing, including voltage monitoring, insertion detection, and controlled power ramp-up/down. The device's "compact-PCI friendly silicon" designation in Section 1.2 of SCPS051 confirms full hardware-level conformance-not just software-configurable support.

What arbitration schemes does the PCI2250PCM support on the secondary bus?

The PCI2250PCM supports two arbitration configurations on the secondary bus: internal two-tier arbitration for up to four secondary bus masters (managed entirely within the device), or external arbitration using the S_REQ/S_GNT signal pairs. The Arbiter Control Register (Section 5.3) and Arbiter Request Mask Register (Section 5.16) allow runtime selection and masking of individual master requests, enabling flexible priority assignment in multi-master embedded systems.