Go to the named program line if the contents of U(n), when ANDed with argument m, is True (non-zero).

This instruction takes the contents of U(n) and performs a bit by bit AND with m and does a GoTo if the result is non-zero. This gives a mechanism whereby one single byte returned from an SPx peripheral could contain up to 8 individual status bits which can easily be tested individually or in combinations.

This is a low-level instruction associated with the SPLat Expansion Framework. You will most likely never need to know how to use it.