Speaker
Tumanov Alexander
(T.W. Bonner Nuclear Laboratory)
Description
Unprecedented data rates that are expected at the LHC put high demand on the
speed of the detector data acquisition system. The CSC subdetector located in
the Muon Endcaps of the CMS detector has a data readout system equivalent in
size to that of a whole Tevatron detector (60 VME crates in the CSC DAQ equal
to the whole D0 DAQ size).
As a part of the HLT, the CSC data unpacking runs online and it needs to be able
to cope with high data rates online. Early versions of the unpacking code used
bit shifts and masks to unpack binary data. To reduce the unpacking time we
decided to switch to bit field based data unpacking. The switch allowed us to
gain an order of magnitude in speed. In this presentation we explain how bit
field data unpacking works and why it is dramatically faster compared to
conventional bit shift and mask methods.
Summary
We would like to submit either a presentation or a poster on this topic
Author
Tumanov Alexander
(T.W. Bonner Nuclear Laboratory)
Co-author
Wilkinson Rick
(Caltech)
