Notes
Slide Show
Outline
1
LHC Beam Loss Monitor
Threshold Comparator
  • Design Considerations
2
Two Parallel TC Systems
  • 40μs – 10ms (step of 40μs)
  • 250 values (total 4,000 values)
  • 4 time windows
  • 10ms – 100s (step of 320μs)
  • 312,500 values (total 5,000,000 values)
  • 6 time windows
3
Averaging Over 8 Values
  • The 8 value average can be easily done by using a digital Low-Pass filter
  • In a single DSP block a 9-bit 8-tap FIR filter is possible
  • The EP1S20 has 10 DSP blocks available.
  • The coefficient values can be created and analysed either by MATLAB or by QUARTUS II
4
FIR Compiler
  • If cn = 0.125 then the output value will be an average of the 8 values
  • By changing the coefficient values other types of averages can be made
5
Memory Requirements
6
Universal Table (LUT for Th & W)
  • Advantages of a universal table:
  • One table for all monitors
  • Can thoroughly be prepared and checked before it is uploaded.
  • Quick and easy upgraded on all systems when it is needed.
  • Less computation in each system. Read vs. Calculated (Note that 10*16*2 = 320 comparisons on each card)
  • Small enough to be kept internally on an M-RAM block (4Kx144bits).