Texas Instruments SCANSTA112VS/NOPB

Overview

SCANSTA112VS/NOPB from Texas Instruments is a 7-port IEEE 1149.1 (JTAG) multidrop multiplexer supporting hierarchical test bus architecture, 3.0–3.6 V operation, −40°C to +85°C industrial temperature range, and up to 25 MHz TCK frequency for board-level structural test and FPGA/ASIC programming in backplane systems.

For engineers reviewing the SCANSTA112VS/NOPB datasheet, SCANSTA112VS/NOPB pinout, SCANSTA112VS/NOPB application, or SCANSTA112VS/NOPB equivalent, this device enables selective access to individual local scan chains across multidrop backplanes, supports transparent/stitcher modes for ATPG vector compatibility, and provides bidirectional master/slave port configuration for alternate test master takeover.

Technical Context

The SCANSTA112VS/NOPB implements dual-level IEEE 1149.1 protocol extension: Level-1 addressing selects specific devices on a shared backplane using 8-slot inputs (supporting up to 249 unique addresses), while Level-2 port selection configures one or more of its seven local scan ports (LSP0–LSP6) into serial or grouped scan chains. Its TAP controller manages instruction register loading, mode register control (Mode Register 0), and 32-bit TCK counter for built-in self-test coordination.

It features bidirectional backplane ports (B0/B1) with master/slave logic, TRST-aware local port control, OE-driven tri-state capability for external test master arbitration, and pass-through A/Y pins for flash programming pulses or status monitoring - all operating within strict IEEE 1149.1 timing constraints including 2.5 ns TMS setup and 3.0 ns TDI setup relative to TCK.

Key Specifications

Pinout & Package

SCANSTA112VS/NOPB is packaged in a 100-pin NFBGA (NZD) with 0.8 mm pitch, RoHS-compliant matte tin (SNAGCU) finish, and MSL Level-4 moisture sensitivity rating (260°C peak reflow, 72-hour floor life).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar IEEE 1149.1 multidrop multiplexer applications.

Compared with SCANSTA111VS/NOPB and SCANPSC110SM/NOPB, SCANSTA112VS/NOPB delivers expanded port count, enhanced address space, and critical ATPG-enabling modes - making it the only option for scalable, future-proof JTAG infrastructure in high-density modular systems.

Availability

SCANSTA112VS/NOPB is available at Aetrix Electronics and suitable for industrial backplane test systems, modular telecom equipment, FPGA-based prototyping platforms, and high-reliability embedded computing requiring stable component supply and long-term lifecycle support.

Supply support for SCANSTA112VS/NOPB 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 leader specializing in analog, embedded processing, and connectivity technologies, with decades of leadership in test and debug infrastructure ICs.

The SCANSTA112VS/NOPB belongs to TI's IEEE 1149.1 boundary-scan support product line, designed specifically to solve scalability, isolation, and system-level access challenges in complex modular electronics.

FAQ

What is the primary function of SCANSTA112VS/NOPB in a JTAG test architecture?

SCANSTA112VS/NOPB functions as a multidrop-capable IEEE 1149.1 multiplexer that extends a single test bus to manage up to seven independent local scan chains. It enables hierarchical and addressable access across backplane-connected boards, allowing selective activation of specific LSPs while maintaining isolation between devices - a core capability for scalable structural test in modular systems.

Does SCANSTA112VS/NOPB support both ScanBridge and Stitcher modes, and how do they differ?

Yes, SCANSTA112VS/NOPB supports both modes. ScanBridge mode uses Level-1 (slot address) and Level-2 (port selection) protocols for full configurability, while Stitcher mode bypasses both levels via external pins (SB/S, TRANS) to enter operational mode directly - reducing test setup latency and simplifying FPGA configuration sequences where dynamic reconfiguration is unnecessary.

Can SCANSTA112VS/NOPB operate in transparent mode, and what is its practical benefit?

Yes, SCANSTA112VS/NOPB supports transparent mode, activated via instruction or pin control, which removes its internal registers and pad-bits from the scan chain. This allows legacy ATPG vectors - originally generated for direct-connected JTAG devices - to be reused without modification, significantly accelerating test program development and validation cycles.

How does the bidirectional backplane port design of SCANSTA112VS/NOPB improve system test flexibility?

The bidirectional B0/B1 ports in SCANSTA112VS/NOPB allow either to serve as master or slave based on MPselB1/B0 control. When configured as slave, LSP0 becomes an alternate master port - enabling external test controllers (e.g., on a daughterboard) to take over scan chain control without modifying PCB layout or requiring additional level-shifting circuitry.

What are the key electrical and timing specifications that ensure SCANSTA112VS/NOPB interoperability with standard JTAG devices?

SCANSTA112VS/NOPB meets IEEE 1149.1 electrical requirements: VIH ≥ 2.1 V, VIL ≤ 0.8 V, VOH ≥ 2.4 V at 12 mA, VOL ≤ 0.4 V at 12 mA, and supports 25 MHz TCK with verified setup/hold (e.g., 3.0 ns TDI setup). Its TMS/TCK/TDO drive strengths (24 mA/12 mA) and controlled slew rates ensure reliable signal integrity across typical backplane trace lengths.