An integrity check of the BS chains
requires a description of the BS architecture present in the BS components
present (obtainable from the SN74BCT8244 data sheet), and information
concerning their location in the board-level BS chain. These two types of
information are merged in table 1 below.
Notice that only that information which is not pre-defined is required, such as the code of the S/P mandatory instruction, or the length of the instruction register and its contents following a Capture-IR operation (the two bits closest to TDO are pre-defined, but the remaining bits might be used to capture relevant information).