Diodes Incorporated PI7C9X112SLFDE

Overview

PI7C9X112SL from Diodes Incorporated is a PCI Express-to-PCI bridge IC enabling legacy PCI peripherals to interface with PCIe 1.0a root complexes. It supports x1 PCIe upstream link, 33 MHz/32-bit PCI bus, and transparent bridging mode with 256-byte configuration space. Designed for industrial control backplanes and embedded computing upgrades, it operates across commercial temperature range (0°C to +70°C) with 3.3 V I/O and 1.8 V core supply.

For engineers reviewing the PI7C9X112SL datasheet, PI7C9X112SL pinout, PI7C9X112SL application, or PI7C9X112SL equivalent, key selection criteria include PCIe 1.0a compliance, PCI bus timing tolerance (±1 ns setup/hold), integrated JTAG boundary scan, and support for memory-mapped I/O translation between 32-bit PCIe and 32-bit PCI address spaces.

Technical Context

The PI7C9X112SL implements a unidirectional forward bridge architecture: PCIe TLPs are converted into PCI transaction packets using on-chip buffering and protocol translation logic. It supports Type 0 and Type 1 configuration cycles, memory write posting, and split-transaction handling for both upstream and downstream traffic.

It features configurable BAR decoding (I/O, memory, prefetchable memory), programmable latency timers (primary/secondary), and hardware-based address translation for 32-bit PCI memory windows mapped into PCIe address space. Power management includes L0s/L1 entry support and CLKRUN# signaling per PCI Express Base Specification 1.0a.

Key Specifications

Pinout & Package

PI7C9X112SL is housed in a 256-pin PBGA package (17 mm × 17 mm, 1.0 mm pitch) with thermal pad. Pin assignments follow JEDEC MO-251 standard and include dedicated differential PCIe TX/RX pairs, PCI AD[31:0], C/BE[3:0]#, PAR, REQ#/GNT#, and mode-strapping pins (MODE[2:0]).

Key Features

Applications

Equivalent & Alternatives

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

Compared with PI7C9X112SL, the PI7C9X110SL offers identical timing and electrical behavior but omits debug and field-update features, while the ASM1083 provides higher speed and flexibility at the cost of design complexity and firmware dependency.

Availability

PI7C9X112SL is available at Aetrix Electronics and suitable for industrial backplane upgrades, legacy test equipment interfaces, and embedded control systems requiring stable component supply over extended product lifecycles.

Supply support for PI7C9X112SL 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and integrated circuits headquartered in California, specializing in high-reliability interface, power management, and signal integrity solutions.

The PI7C9X112SL belongs to Diodes' PCI Express bridge product line, engineered specifically for seamless integration of legacy PCI peripherals into modern PCIe-based platforms without driver or firmware changes.

FAQ

Does PI7C9X112SL support PCIe 2.0 or higher?

No. The PI7C9X112SL is strictly compliant with PCI Express Base Specification 1.0a and operates at 2.5 GT/s (Gen 1). It does not negotiate or function at 5 GT/s (Gen 2) or higher speeds. Attempting to connect it to a Gen 2+ root port results in fallback to Gen 1 link training, confirmed in Section 2.2 of DS40299 Rev 5.

Can PI7C9X112SL operate in reverse bridging mode (PCI-to-PCIe)?

No. Reverse bridging was explicitly removed starting with Revision 1.2 of the datasheet (February 2010) and is not supported in any revision thereafter, including Rev 5. The device functions exclusively as a forward bridge (PCIe → PCI), as stated in Section 4 and confirmed in the "Functional Mode Selection" table (Section 3.1).

What EEPROM types are supported for auto-load configuration?

The PI7C9X112SL supports standard SPI serial EEPROMs with 256-byte page size and up to 256 KB capacity, using standard SPI opcodes (0x03 Read, 0x02 Write, 0x06 Write Enable). It requires external pull-up on HOLD# and WP# pins and validates checksums over the first 256 bytes of loaded configuration data.

Is JTAG boundary scan mandatory for functional operation?

No. JTAG is optional and disabled by default; the device operates fully without JTAG connection. Pins TCK/TMS/TDI/TDO may be left unconnected or tied to appropriate voltage levels. Boundary scan is intended solely for board-level test and debug-not required for runtime functionality per Section 2.5 and Table 2-1.