HSI - Read-out/Buffering and Formatting
Introduction
The analogue data produced by an event in the detectors is converted to digital
data and buffered in front end modules. Part of this data is sent to a first
level trigger processor. The decision of the first level trigger processor to
accept or reject the event is transmitted to the readout modules. These modules
read the accepted event fragments into a internal buffer. Again some data is
sent to the second level trigger. Upon receiving the decision from the second
level trigger, the readout module formats the data and sends it to the event
builder whose role is to combine the event fragments from different readout
modules. In an LHC experiment, several hundred readout modules will be
required.
The readout module should be able to
- Read event fragments from front end modules on level one trigger
- Buffer the fragments until readout is requested (up to 5MBytes)
- Accept the destination address of the event fragments
- Format the data for transmission to the event builder
- Perform traffic shaping
- Provide 100MBytes/sec. throughput
Readout for Different Technologies
Reiner Hauser (Reiner.Hauser@cern.ch)