Advances in integration technologies, right through to 3D integrated circuits, make it possible today to create complete systems on one chip in the form of a SoC (System-on-Chip). For this purpose, Embedded System Access (ESA) technologies are indispensable to test such highly integrated systems. ESA has made it possible to adopt entirely new approaches to holistic testing, including:

  • Hierarchical testing (chip, board, unit)
  • Product life cycle test (laboratory, production, field)
  • System level testing

ESA technologies are utilized both for testing chips, boards, and system assemblies, as well as for on-board programming of non-volatile memory:

  • JTAG/Boundary Scan (BST)
  • Processor Emulation Test (PET)
  • Chip-embedded Instruments (IJTAG)
  • Embedded Diagnostics Test (EDT)
  • In-System Programming (ISP)
  • FPGA-Assisted Programming (FAP)
  • Core-Assisted Programming (CAP)
  • In-Application Programming (IAP)

The common feature of these technologies is that they all use a serial test bus for communication purposes; their properties and methods differ, however.