See also, the legacy SJTAG FAQ page.
Q: What is STAM?
Q: Does SJTAG still exist?
Q: Do I need to be an IEEE member to be part of the STAM Working Group?
Q: How do I join the STAM Working Group?
Q: Don't the existing standards already deal with this?
Q: When can we expect the STAM standard to be published?
A: STAM (P2654) or System Test Access Management aims to assist test developers with constructing tests of boards, sub-assemblies and systems, especially where the test involves the use of multiple, diverse types of interface, for example where the stimulus for the test may be applied using IEEE 1149.1 methods but the observed test result needs to be retrieved using SPI.
A: Yes, but SJTAG is no longer expected to be a single standard in its own right and should be considered as an overarching initiative on system test with STAM being the first standardisation project within that initiative.
A: No, membership of the Working Group is open to anyone who has interest in helping with developing the STAM standard. Officers of the group are however required to be IEEE and Standards Association members.
A: Not really. Most test interface/protocol standards such as IEEE 1149.1 or IEEE 1687 really only define what happens within a single device or a single network and are predominantly focussed on getting data to or from some register. They don't, for example, handle aspects such as the time sequencing of when a "sense" instruction is applied in relation to a "stimulus" instruction such that the test will behave as expected. This becomes more of an issue when different interfaces are involved and/or the test spans across different devices or board edges.
A: That is difficult to predict with certainty, however the P2654 project is approved through to the end of December 2022, in line with the standard 4-year timescale applied to new standards development projects. On that basis we would expect to move to formal balloting on the draft standard by mid-2022 with final IEEE approval early in 2023