A bus interface module ("BIM") connectable to a debug bus is described. In
one embodiment, the BIM comprises a plurality of BIM segments connected
in a ring such that an output of each BIM is connected to an input of a
next BIM via the debug bus, the BIM comprising logic for receiving data
from a previous BIM, logic for receiving data from local logic associated
with the BIM, and logic for combining the previous BIM data with local
logic data and transmitting the combined data to a next BIM.