Texas Instruments TNETX15VEPGE

Overview

TNETX15VEPGE from Texas Instruments is a VLAN-engine address-lookup device designed to perform hardware-accelerated MAC address matching and forwarding decisions for the TNETX3150/TNETX3150A Ethernet switch. It supports up to 2K address entries, provides glueless EAM interface connectivity, integrates JTAG-compliant boundary-scan test logic, and enables VLAN-aware routing with spanning-tree support in managed or unmanaged mode.

For engineers reviewing the TNETX15VEPGE datasheet, TNETX15VEPGE pinout, TNETX15VEPGE application, or TNETX15VEPGE equivalent, this device is critical for Ethernet switch designs requiring deterministic address lookup, secure port-based forwarding, EEPROM auto-configuration without CPU involvement, and MII-managed PHY control via MDIO/MDCLK.

Technical Context

The TNETX15VEPGE operates as a dedicated offload engine interfacing directly with the TNETX3150/TNETX3150A DRAM bus to extract frame headers, source/destination MAC addresses, VLAN tags, and port identifiers. Its internal arbiter prioritizes wire-speed LOOKUP operations over DELETE, ADD, FIND, and AGE functions, ensuring real-time forwarding decisions.

Address storage relies on external ×16 SRAM (up to 4K entries), while internal 4K×16 SRAM manages FIFOs for BPDU handling and bus-watcher metadata. The device implements dual-mode EAM output-single-port (EAM15=1) for unicast and multiple-port (EAM15=0) for VLAN multicast-with discard code 0x0000 and IEEE 802.1D spanning-tree BPDU support.

Key Specifications

Pinout & Package

Packaged in 144-terminal plastic quad flatpack (PGE), the TNETX15VEPGE features dedicated buses for external SRAM (EA20–EA0, ED15–ED0, EOE, EWE), DRAM monitoring (DD35–DD0, DRAS, DCAS, DWE), EAM routing output (EAM15–EAM0), DIO management (SAD1–SAD0, SDATA7–SDATA0, SRNW, SRDY, ESCS), MDIO interface (MDIO, MDCLK, MRESET), EEPROM (EDIO, ECLK), and JTAG (TRST, TMS, TCLK, TDI, TDO).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar VLAN-aware address-lookup applications.

Compared with TNETX15V and TNETX15VPGE, the TNETX15VEPGE offers updated aging logic initialization, clarified EEPROM loading sequence, and formalized support for VLAN multicast coding - making it the recommended choice for new ThunderSWITCH-based switch designs requiring long-term supply stability and documented compliance with SPWS028B.

Availability

TNETX15VEPGE is available at Aetrix Electronics and suitable for managed Ethernet switches, unmanaged SOHO switches, and VLAN-aware uplink expansion modules requiring stable component supply, long-lifecycle support, and compatibility with legacy ThunderSWITCH platforms.

Supply support for TNETX15VEPGE 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 founded in 1930, specializing in analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The TNETX15VEPGE belongs to TI's ThunderSWITCH family of Ethernet switching ICs, engineered specifically to enable scalable, low-latency Layer 2 switching with hardware-accelerated VLAN and spanning-tree functionality for carrier-grade and enterprise infrastructure.

FAQ

What is the primary function of the TNETX15VEPGE in an Ethernet switch system?

The TNETX15VEPGE serves as a dedicated VLAN-engine address-lookup device that performs real-time MAC address matching, VLAN-aware forwarding decisions, and spanning-tree BPDU handling for the TNETX3150/TNETX3150A ThunderSWITCH. It interfaces gluelessly via the EAM bus and offloads these functions from the main switch fabric, enabling deterministic latency and reduced host CPU involvement in TNETX15VEPGE-based systems.

Does the TNETX15VEPGE require an external microprocessor to operate?

No - the TNETX15VEPGE supports unmanaged operation via EEPROM auto-configuration: startup register values are loaded from an external x24C02 EEPROM at reset, enabling fully autonomous address learning and forwarding without any microprocessor. However, a microprocessor can be attached via the DIO interface for managed operation, statistics monitoring, and dynamic table updates in TNETX15VEPGE-based systems.

How does the TNETX15VEPGE handle VLAN multicast routing?

The TNETX15VEPGE uses its 16-bit EAM interface to output multi-port routing codes when EAM15=0: each bit EAM14–EAM0 corresponds to ports 01–14 (plus uplink port 00), where a '1' enables forwarding to that port. For example, multicast to ports 08/05/02/00 maps to EAM15–EAM0 = 0x0125. This native VLAN-aware coding eliminates software-based packet replication in TNETX15VEPGE-integrated switch designs.

What power supply requirements does the TNETX15VEPGE have?

The TNETX15VEPGE requires two independent supplies: a 3.3-V rail for core logic operation and a 5-V rail for I/O buffer biasing. All digital I/O pins (EAM, DRAM, SRAM, DIO, MDIO) are 5-V tolerant, allowing direct interfacing with 5-V peripherals without level shifters - a key design consideration for TNETX15VEPGE integration into mixed-voltage Ethernet switch platforms.

Is the TNETX15VEPGE JTAG-compliant, and what are the implementation requirements?

Yes, the TNETX15VEPGE implements full IEEE Std 1149.1 JTAG boundary-scan functionality on TRST, TMS, TCLK, TDI, and TDO pins. However, TI specifies that external pullup resistors must be applied to TDI, TMS, and TRST to ensure proper test-port initialization - a mandatory requirement for reliable board-level testing and debug in TNETX15VEPGE-based products.