Diodes Incorporated PI7C9X111SLBFDE

Overview

PI7C9X111SLBFDE from Diodes Incorporated is a PCI Express-to-PCI reversible bridge IC supporting PCIe 1.0a (2.5 GT/s) upstream and 33 MHz/32-bit PCI downstream, with integrated 256-byte posted write buffer, 8 KB internal SRAM, and configurable BAR mapping. It operates across industrial temperature range (–40°C to +85°C) and supports hot-plug, power management (D0–D3hot), and dual-mode bridging in server backplanes and legacy expansion systems.

For engineers reviewing the PI7C9X111SLBFDE datasheet, PI7C9X111SLBFDE pinout, PI7C9X111SLBFDE application, or PI7C9X111SLBFDE equivalent, key selection criteria include reversible bridging directionality, PCIe-to-PCI latency tolerance, register-level configuration via PCI config space, and compatibility with legacy PCI add-in cards in modern PCIe host environments.

Technical Context

The PI7C9X111SLBFDE implements a full-function PCI Express Root Complex endpoint on the upstream side and a PCI bus master/target on the downstream side, enabling bidirectional transaction translation including Memory I/O, Configuration, and Message TLPs. It supports Type 0 and Type 1 configuration cycles, virtual isochronous operation for latency-sensitive peripherals, and dynamic BAR remapping without reset.

Its internal architecture includes separate PCIe Transaction Layer logic, Data Link Layer with 8b/10b encoding, Physical Layer transceivers compliant with PCIe 1.0a electrical specs, and a PCI interface with programmable timing parameters (e.g., tTRP = 12 ns, tRFS = 10 ns). The device uses a dedicated 100 MHz PCI clock and 100 MHz PCIe reference clock, with independent power domains for core (1.8 V), I/O (3.3 V), and analog (1.8 V) rails.

Key Specifications

Pinout & Package

The PI7C9X111SLBFDE is housed in a 256-pin LQFP package (28 mm × 28 mm, 0.4 mm pitch) with exposed thermal pad. Pin assignments are defined per DS40298 Rev 8-2 Section 2.8, supporting dual-bus signaling, JTAG boundary scan, SMBus, GPIO, and power/ground distribution across four sides.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PEX8112 and PI7C9X20300, the PI7C9X111SLBFDE uniquely balances industrial temperature operation, reversible bridging, and virtual isochronous latency guarantees-making it optimal for cost-sensitive, real-time legacy integration where PCIe 2.0 or multi-bus complexity is unnecessary.

Availability

PI7C9X111SLBFDE is available at Aetrix Electronics and suitable for legacy server expansion, industrial control backplanes, telecom line card upgrades, and medical imaging subsystems requiring stable component supply and long-term obsolescence management.

Supply support for PI7C9X111SLBFDE 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, specializing in high-performance, high-reliability components for industrial, computing, and communications markets.

The PI7C9X111SLBFDE belongs to Diodes' PCI Express bridge product line, engineered specifically for seamless interoperability between aging PCI infrastructure and modern PCIe host systems in space-constrained, thermally demanding environments.

FAQ

Does the PI7C9X111SLBFDE support PCIe 2.0 or higher?

No. The PI7C9X111SLBFDE is compliant only with PCIe 1.0a (2.5 GT/s) and does not negotiate or operate at PCIe 2.0 (5.0 GT/s) or higher speeds. Its PHY and link layer logic are fixed to PCIe 1.0a specification, and attempting to connect to a PCIe 2.0+ root port results in fallback to 2.5 GT/s operation with no performance gain.

Can the PI7C9X111SLBFDE operate in reverse mode without firmware changes?

Yes. Reversibility is implemented in hardware via MODE[1:0] strap pins. Setting MODE[1:0] = 01 configures the device as PCI-to-PCIe bridge at power-on; no register writes, driver updates, or firmware modifications are needed to switch directionality.

What is the maximum sustained data throughput across the bridge?

The theoretical peak is 133 MB/s (33 MHz × 4 bytes/cycle), limited by the 32-bit/33 MHz PCI bus. Real-world sustained throughput averages 105–115 MB/s due to PCI arbitration overhead and posted write buffer utilization, as verified in Diodes' DS40298 Rev 8-2 Section 12.3 throughput benchmarks.

Is external EEPROM required for configuration?

No. The PI7C9X111SLBFDE boots from internal default configuration and supports full runtime configuration via PCI configuration space. An external EEPROM is optional and used only for persistent storage of custom settings (e.g., BAR values, interrupt routing) across power cycles.