UT subsector bit handling
The 9th bit of UT channelID
determines its subsector (a sector can have 2 subsector). However, UT stripID
can range from [0, 511] within a sector, so stripID
will use 9 bits. When calculating UT LHCbID, it is
unsigned LHCbID = channelID + stripID;
but when stripID is between [256, 511], both the subsector bit (9th bit) in channelID
and the 9th bit in stripID
will be redundantly set to 1. This will cause LHCbID
to be off by 256. The fix to this is to mask the last 9 bits of UT channelID
(this is what Rec
does, so I implemented this to be consistent in Allen
).
The equivalent MR for HLT2 is Rec!3880 (merged).
Edited by Da Yu Tou