RCU

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RCU DCS system in ALICE

• RCU design, prototyping and test results (TPC
  PHOS)

Johan Alme
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Content

• Overview
• RCU - Read Out Control Unit
• DCS Detector Control System
• Event Readout
• Test results
• Ongoing Work

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Overview
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RCU Read Out Control Unit

• Hardware entirely developed by Bergen.
• Firmware a collaboration between Bergen and CERN
• Tasks
• Shipping event data from the Front End Cards to
  the DAQ (Data Aquisition)
• Distributing Triggers
• Communication with the Front End Electronics

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RCU Architecture
RCU
Trigger information
Trigger IF
Status Register
Slow Control Active FEC list
DCS
FEC
I2C Bus
Command Interpreter Bus Switch
RCU Bus has been tested in a 12h stress-test with
approximate 200 billion transactions without any
error
RCU bus
SIU interface
ALTRO IF Instuction Mem Result Mem Active Ch.
List
FEC
SIU
Data Assembler
Altro Bus
DATA PATH
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DCS - Detector Control System

• Collaboration between Bergen and Heidelberg
• Tasks
• Configuring the RCU FPGA
• Configuring the Frond End Electronics Cards (FEE)
• Monitoring/Controlling of the FEEs
• Configuration of the Trigger system.

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DCS Architecture
ARM Processor
Dim connector (RCU)
RCU bus
Ethernet
Ethernet IF
RCU Bus IF
JTAG
JTAG master
RCU FPGA Config
ADCs
ADC readout
TTCRX
Triggerinfo
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Firmware/Software on DCS
DIM client
Direct login (SSH)
Intercom layer
Shell
DIM server
Linux Kernel
Software
Driver
Module Interfaces
Firmware (FPGA)

• Direct Login via SSH used in TPC and PHOS
  beamtests.
• DIM server and DIM client development is ongoing.

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Event Readout example
Linuxshell sendRCUcommand
1. Configure system to wait for trigger
2. FEC collects data when L1 trigger.
3. RCU reads event when L2a trigger and ships it
through the datapath to the DAQ.
4. When done, RCU again waits for new trigger.
DCS
RCU
Trigger info
Trigger IF
Daq
FECs
L2 accept Trigger
FEC
FEC
L1 Trigger
FEC
Altro IF
Data Assembler
SIU IF
Buffering event...
Important Only RCU FPGA is directly in the
datapath.
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Configuration Readout
Overall configuration data 7MB/RCU Worst case
scenario

• 3200 active channels
• 1000 samples/channel

lt 1 s
0.7 s
3 s
RCU
FEC
Transporter to DCS scripts
buffer
FEC
Readout 3 ms
? Max 4,7 s for configuration
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TPC Beamtest results
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Test results

• Successfully used in the TPC beamtest.
• Successfully used in the PHOS beamtest.
• More systems are running smoothly in a lab
  environment.

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Ongoing work

• Change the FPGA on the RCU board from Altera to
  Xilinx for better handling of radiation
• Test-card
• New RCU board prototype (? Mass production late
  2005)
• Hardware Firmware for automatic reconfiguring
  of RCU
• Extensive testing of radiation harness
• Firmware for voltage and temperature measurements
• Firmware for trigger interface module.