Title: Some Details on CKM Data Format
1Some Details on CKM Data Format
- Jinyuan Wu
- for CKM Collaboration
- April 2002
2Questions
3Q TDC Word Bit Layout
0
TS of Hit
TDC
0
TS of Hit
TDC
- The rearrangement is very useful.
- TDC word represents unique time.
- TDC ordering represents hit ordering.
- Caution TS and TDC are in different units
convert unit while calculating DT.
4Q Error Checking
- Its important to consider it from beginning.
- A check sum word is attached at the end of a
centenary. (Place holder only for now).
5Centenaries (TDC Example)
Check sum word
C. 1
TDC data
Roll-over Marker
Check sum word
C. 0
TDC data
Roll-over Marker
6TDC Data
Roll-over Marker
TS96
1
Ch.
0
1
0
1
Check sum of past centenary
1
Check sum word
1
0
TS70
0
E
TDC data
Time (1ns/bin)
D
Error bit
Earliest Time from CLK leading edge
Double hit marker from TDC
7Q Centenary, Millenary
- A centenary is 256 CLK cycles. (Or 2.5 to 6.4
ms). - A millenary could be 256 centenaries. (Or 0.65
to 1.6 ms. Use 256 for now, should be determined
after having knowledge about switch).
8Millenary Structure
Centenary 255
Centenary 0
Centenary ID word Inserted while forming
Millenary
Millenary Header
9Millenary Header Words
Centenary ID One for each centenary
Centenary ID TS158
1
0
1
0
Optional Redundant check information. Inserted
after collecting the whole Millenary
Millenary Check Sum 110
1
1
1
1
Millenary Word Count 2312
1
1
1
1
Millenary Word Count 110
1
1
1
1
Unified Channel Number 2312
1
1
1
1
Unified Channel Number 110
1
1
1
1
Millenary ID 3124
1
1
1
1
Reset ID 30
Millenary ID 2312
1
1
1
1
The 2nd header word
The 1st header word
Millenary ID 110
1
1
1
0
10Remarks on Millenary
- Both header identification and data block size
mechanisms are allowed. - Header identification is preferred.
- Word count and check sum are used as redundant
check.
11Q Hitlet?
- Suggested module for now direct pipeline dump.
- When over-threshold data exist, dump
- Header.
- 2 empty slots.
- Over-threshold slots.
- 2 empty tail slots.
- Any other data fragments can be chopped from the
pipeline dump in software.
12Q (QIETDC) or (QIE)(TDC)?
- There is a possibility TDC and QIE data exist in
same chip. - Hardware effort is the same for (QIETDC) or
(QIE)(TDC). - (QIETDC) might have advantage in software stage.
- Suggestion leave both schemes possible, defer
the choice until the trigger study result comes
out.
13Veto System Data
Roll-over Marker
TS96
1
Ch.
0
1
0
TS90
1
0
E
Hitlet Header
QIE (2 range, 6 mantissa)
0
0
CapID
QIE only data
(QIETDC) data
0
1
QIE (2 range, 6 mantissa)
Time (1ns/bin)
D
1
Check sum of past centenary
1
Check sum word
1
0
14Hitlets, Centenary
Check sum word
(QIETDC) data
QIE only data
Hitlet Header
Roll-over Marker
15Summary (1) (QIETDC) Data
Hitlet
Millenary
Centenary
2 Empty QIE words
Centenary 255
QIE(TDC) word(s)
Check Sum
0-42 Hitlets, 0-255 words
2 Empty QIE words
Hitlet Hdr.
Centenary 1
Roll-over marker Centenary ID
Centenary 0
M. Header
16Further Saving
- Use centenary ID only (eliminate roll-over
marker). - Eliminate empty centenaries.
- Suggestion dont worry about it for now but keep
it in mind.
17Summary (2) TDC Data
Millenary
Centenary
Centenary 255
Check Sum
0-255 TDC words
Centenary 1
Roll-over marker Centenary ID
Centenary 0
M. Header
18The End