Draft 0.01

                    Drift Chamber to Level 3 Trigger

                         Interface Specification

                            Aug 7, 1997

This specification outlines the special needs of Level 3 (L3) 
as imposed on the DCH.

Minimal data content to be transmitted
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wire id
time stamp 


These data should be zero-suppressed for speeding up subsequent
unpacking, meaning a list containing non-zero hits are to be
delivered.

Additional data derived in the ROM
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None at the moment.

Formatting
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Name			Format		Unit

wire id   		to be determined
time stamp		to be determined

Order of wires could have significant impact on the speed of
the L3 unpacking algorithm, this will need further study.