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Some Details on CKM Data Format. Jinyuan Wu for CKM Collaboration April 2002. Questions. Q: TDC Word Bit Layout. 0. TDC. TS of Hit. The rearrangement is very useful. TDC word represents unique time. TDC ordering represents hit ordering.
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Some Details on CKM Data Format Jinyuan Wu for CKM Collaboration April 2002
Q: TDC Word Bit Layout 0 TDC TS of Hit • 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. 0 TS of Hit TDC
Q: Error Checking • It’s important to consider it from beginning. • A check sum word is attached at the end of a centenary. (Place holder only for now).
1 1 1 1 0 0 0 0 TS[9:6] TS[9:6] Ch. # Ch. # 1 1 1 1 0 0 1 1 Check sum of past centenary Check sum of past centenary 0 0 0 0 0 0 0 0 0 E E E E E E E E E D D D D D D D D D TS[7:0] TS[7:0] TS[7:0] TS[7:0] TS[7:0] TS[7:0] TS[7:0] TS[7:0] TS[7:0] Time (1ns/bin) Time (1ns/bin) Time (1ns/bin) Time (1ns/bin) Time (1ns/bin) Time (1ns/bin) Time (1ns/bin) Time (1ns/bin) Time (1ns/bin) Centenaries: (TDC Example) Check sum word C. 1 TDC data Roll-over Marker Check sum word C. 0 TDC data Roll-over Marker
15 8 7 0 TDC Data Roll-over Marker 1 1 0 0 TS[9:6] Ch. # Check sum word 1 1 0 1 Check sum of past centenary TDC data 0 E D TS[7:0] Time (1ns/bin) Error bit Earliest Time from CLK leading edge Double hit marker from TDC
Q: 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).
1 1 1 1 0 0 0 0 TS[9:6] TS[9:6] Ch. # Ch. # 1 1 1 1 0 0 1 1 Check sum of past centenary Check sum of past centenary 0 0 0 E E E D D D TS[7:0] TS[7:0] TS[7:0] Time (1ns/bin) Time (1ns/bin) Time (1ns/bin) 1 1 1 1 0 0 0 0 Centenary ID = TS[15:8] Centenary ID = TS[15:8] 1 1 1 1 Millenary Check Sum [11:0] 1 1 1 1 Millenary Word Count [23:12] 1 1 1 1 Millenary Word Count [11:0] 1 1 1 1 Unified Channel Number [23:12] 1 1 1 1 Unified Channel Number [11:0] 1 1 1 1 Reset ID [3:0] Millenary ID [31:24] 1 1 1 1 Millenary ID [23:12] 1 1 1 0 Millenary ID [11:0] Millenary Structure Centenary 255 Centenary 0 Centenary ID word: Inserted while forming Millenary Millenary Header
15 8 7 0 Millenary Header Words Centenary ID One for each centenary 1 1 0 0 Centenary ID = TS[15:8] Optional Redundant check information. Inserted after collecting the whole Millenary 1 1 1 1 Millenary Check Sum [11:0] 1 1 1 1 Millenary Word Count [23:12] 1 1 1 1 Millenary Word Count [11:0] 1 1 1 1 Unified Channel Number [23:12] 1 1 1 1 Unified Channel Number [11:0] 1 1 1 1 Reset ID [3:0] Millenary ID [31:24] The 2nd header word 1 1 1 1 Millenary ID [23:12] The 1st header word 1 1 1 0 Millenary ID [11:0]
Remarks 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.
0-4 0-4 0-4 0-4 0-4 5 7 0-4 5 6 9 0-4 0-4 0-4 Hitlet Hdr 0-4 Q: 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.
PMT QIE TDC Q: (QIE+TDC) or (QIE)+(TDC)? • There is a possibility TDC and QIE data exist in same chip. • Hardware effort is the same for (QIE+TDC) or (QIE)+(TDC). • (QIE+TDC) might have advantage in software stage. • Suggestion: leave both schemes possible, defer the choice until the trigger study result comes out.
15 8 7 0 Veto System Data Roll-over Marker 1 1 0 0 TS[9:6] Ch. # Hitlet Header 1 0 E TS[9:0] QIE only data 0 0 CapID QIE (2 range, 6 mantissa) (QIE+TDC) data 0 1 D Time (1ns/bin) QIE (2 range, 6 mantissa) Check sum word 1 1 0 1 Check sum of past centenary
1 1 0 0 TS[9:6] Ch. # 1 1 0 0 E E TS[9:0] TS[9:0] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CapID CapID CapID CapID CapID CapID CapID CapID CapID CapID CapID QIE (2 range, 6 mantissa) QIE (2 range, 6 mantissa) QIE (2 range, 6 mantissa) QIE (2 range, 6 mantissa) QIE (2 range, 6 mantissa) QIE (2 range, 6 mantissa) QIE (2 range, 6 mantissa) QIE (2 range, 6 mantissa) QIE (2 range, 6 mantissa) QIE (2 range, 6 mantissa) QIE (2 range, 6 mantissa) 0 1 D Time (1ns/bin) QIE (2 range, 6 mantissa) 1 1 0 1 Check sum of past centenary Hitlets, Centenary Check sum word (QIE+TDC) data QIE only data Hitlet Header Roll-over Marker
Summary (1): (QIE+TDC) 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
Further Saving • Use centenary ID only (eliminate roll-over marker). • Eliminate empty centenaries. • Suggestion: don’t worry about it for now but keep it in mind.
Summary (2): TDC Data Millenary Centenary Centenary 255 Check Sum 0-255 TDC words Centenary 1 Roll-over marker Centenary ID Centenary 0 M. Header
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