Register

[Bradford Van Treuren]

This post is about the term "Register" and how that relates to P2654, P1687.1, 1687, and 1149.1-2013. Qualifying adjectives are also discussed.

From IEEE 1149.1-2013:
Register: Most often a Test Data Register, which is accessed by one or more specific instructions. (See Clause 9.)

selected test data register: A test data register is selected when it is required to operate by an instruction supplied to the test logic.

From IEEE 1687-2014:
Register: One or more storage elements that share a name and whose bits are arranged as a vector range (e.g., MyReg[31:0]).

data register: A set of one or more storage cells with a parallel input and a parallel output.

From IEEE 1149.10-2017:
instruction register: Refers to the IEEE 1149.1 instruction register. Bit “I” of the ICSU defined section in the scan packet indicates if there is an operation from a HSTAP and PEDDA to an IEEE 1149.1 instruction register. All other “instruction” registers, such as the IEEE 1500 wrapper instruction register, are treated as IEEE 1149.1 test data registers.

[Bradford Van Treuren]

Jeff Rearick proposed this definition in an email.
Portal Register: an addressable register accessible through a functional interface to which writes and reads interact with a 1687 serial access network
Michele commented: Do we really need it in the definitions? It is not just part of the informative part of the standard, as a possible composition of the base elements (like the SIB)?