Diodes Incorporated PI7C9X2G404EVAZXAEX

Overview

PI7C9X2G404EVAZXAEX from Diodes Incorporated is a PCI Express Gen 2 packet switch IC with 4 downstream ports and 1 upstream port, supporting up to 4 PCIe lanes per port, 2.5 GT/s data rate, 128-byte maximum payload size, and transparent bridging mode for root complex extension in embedded computing systems.

For engineers reviewing the PI7C9X2G404EVAZXAEX datasheet, PI7C9X2G404EVAZXAEX pinout, PI7C9X2G404EVAZXAEX application, or PI7C9X2G404EVAZXAEX equivalent, key selection criteria include lane bifurcation support, EEPROM-based configuration flexibility, low-latency routing (<150 ns), and compliance with PCIe Base Spec 2.1 and ECN for L1 Substates.

Technical Context

This switch implements full PCIe 2.0 transaction layer (TLP encapsulation/decapsulation), data link layer (ACK/NAK, flow control), and physical layer (receiver equalization, transmitter de-emphasis) functions across four configurable downstream ports and one upstream port. It supports Type 1 and Type 0 configuration transactions, VC arbitration, and TC/VC mapping with programmable traffic classes.

The device uses a 136-pin AQFN package with integrated 1.0V/1.8V/3.3V power domains, supports hot-plug detection per port, and enables autonomous power state transitions (L0s/L1) without host intervention via hardware-controlled LTSSM management and debugout status registers.

Key Specifications

Pinout & Package

PI7C9X2G404EVAZXAEX is housed in a 136-pin Advanced Quad Flat No-lead (AQFN) package with 0.4 mm pitch, 12 mm × 12 mm body, and exposed thermal pad for enhanced heat dissipation in high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PCIe 2.0 packet switching applications.

Compared with ASM1083 and PI7C9X2G304EV, PI7C9X2G404EVAZXAEX delivers higher port count, autonomous configuration, and hardware-managed power states-making it optimal for scalable, maintenance-aware PCIe expansion in industrial and medical platforms.

Availability

PI7C9X2G404EVAZXAEX is available at Aetrix Electronics and suitable for industrial control gateways, medical imaging data aggregators, test & measurement rack controllers, and avionics data acquisition units requiring stable component supply across extended product lifecycles.

Supply support for PI7C9X2G404EVAZXAEX 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 analog, logic, and interface solutions for industrial, computing, and communications markets.

The PI7C9X2G404EVAZXAEX belongs to Diodes' PCI Express packet switch product line, designed specifically to simplify PCIe topology expansion in resource-constrained embedded systems requiring deterministic latency and field-upgradable configuration.

FAQ

Does PI7C9X2G404EVAZXAEX support PCIe Gen 3?

No. The device is strictly PCIe Gen 2 compliant, operating at 2.5 GT/s with Gen 2-specific PHY parameters including receiver equalization settings, de-emphasis levels, and LTSSM state machine behavior. It does not negotiate Gen 3 speeds or support 8b/10b encoding variants required for Gen 3.

Can the upstream port be configured as a downstream port?

No. The upstream port is hardwired for root complex-facing operation and cannot be reconfigured as a downstream port. Port roles are fixed in silicon: one dedicated upstream port (UPLINK) and four downstream ports (DNLINK0–DNLINK3), each with independent enable/disable control via configuration registers.

What is the minimum EEPROM size required for configuration storage?

A 2-Kbit (256 × 8) I²C EEPROM is sufficient to store full configuration data, including port enable masks, VC mapping tables, and SMBus address settings. The device reads only the first 256 bytes during auto-load; larger EEPROMs are supported but unnecessary for standard use cases.

Is JTAG boundary scan supported for production testing?

Yes. Pins TCK, TMS, TDI, and TDO are fully compliant with IEEE 1149.1, supporting boundary scan testing of solder joints and interconnect integrity on the 136-pin AQFN package. Scan chain length and register definitions are documented in Section 3.4 of the datasheet.