TAB to GAB Data Transmission

updated: 08-Feb-07

Index

TAB to GAB Data Streams

49 separate 12-bit data streams are transmitted from each TAB to the GAB using LVDS signals on 7-pair cables. These are the same cables/connectors as are used for ADF to TAB data transmission, however, LVDS drivers/receivers embedded in the Altera Stratix chips are used to send signals rather than the Channel Link chips used for ADF-to-TAB transmission and the multiplexing is different.

Definitions of the 49 signal lines and their corresponding positions in the LVDS transmission are given in the table below.

          Bit Definitions
Input
bit
 LVDS out
[cable.bit] 		Signal Eta Phi 11 10 09 08 07 06 05 04 03 02 01 00
0 0.0 EM Count S 2 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
1 0.1 EM Count S 3 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
2 0.2 EM Count S 4 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
3 0.3 EM Count S 5 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
4 0.4 EM Count C 2 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
5 0.5 EM Count C 3 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
6 0.6 EM Count C 4 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
7 1.0 EM Count C 5 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
8 1.1 EM Count N 2 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
9 1.2 EM Count N 3 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
10 1.3 EM Count N 4 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
11 1.4 EM Count N 5 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
 
12 1.5 JET Count S 2 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
13 1.6 JET Count S 3 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
14 2.0 JET Count S 4 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
15 2.1 JET Count S 5 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
16 2.2 JET Count C 2 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
17 2.3 JET Count C 3 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
18 2.4 JET Count C 4 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
19 2.5 JET Count C 5 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
20 2.6 JET Count N 2 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
21 3.0 JET Count N 3 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
22 3.1 JET Count N 4 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
23 3.2 JET Count N 5 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
 
24 3.3 TAU Count S 2 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
25 3.4 TAU Count S 3 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
26 3.5 TAU Count S 4 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
27 3.6 TAU Count S 5 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
28 4.0 TAU Count C 2 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
29 4.1 TAU Count C 3 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
30 4.2 TAU Count C 4 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
31 4.3 TAU Count C 5 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
32 4.4 TAU Count N 2 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
33 4.5 TAU Count N 3 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
34 4.6 TAU Count N 4 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
35 5.0 TAU Count N 5 Thr-6 Thr-5 Thr-4 Thr-3 Thr-2 Thr-1
 
36 5.1 EM+H Sum 39-0 5-2 Sum(EM+H Et)
37 5.2 EM+H Sum 39-0 5-2 Sum(EM+H Ex)
38 5.3 EM+H Sum 39-0 5-2 Sum(EM+H Ey)
 
39 5.4 BC Or --- --- 0 OR of BCs from ADFs
40 5.5 Status --- --- Status Register
41 5.6 Sync --- --- Synch Pulse
42 6.0 Valid --- --- Valid
43 6.1 SCL BC --- --- 0 BC calc in TAB
44 6.2 SCL TURN --- --- TURN calc in TAB
45 6.3 EM Iso S --- phi = 5 4 3 2
46 6.4 EM Iso C --- phi = 5 4 3 2
47 6.5 EM Iso N --- phi = 5 4 3 2
 
48 6.6 Parity --- --- Vertical Parity

Notes

  1. Input bit
    Bit stream number for input to serializer in TAB chip 10. Also output bit stream number in corresponding GAB input Stratix.
  2. LVDS out
    Cable pairs are numbered 0-6. Each cable-pair carries 7 bits per cycle, corresponding to 7 data-streams. Multiplexing is shown here
  3. Eta
    The three eta regions: S=South, C=central, N=north. The ieta definitions for these are defined here.
  4. Phi
    This corresponds to the TAB's local phi. Each TAB receives 9 phi-slices (0-8) and finds local maxima in 4 phi-slices (lower-left corners in phi-slices 2-5).
  5. EM Count
    This 12-bit count is broken up into 6 2-bit sections, each corresponding to the number of EM objects (0,1,2,>2) in this eta-phi region over a given threshold.
  6. JET Count
    This 12-bit count is broken up into 6 2-bit sections, each corresponding to the number of JET objects (0,1,2,>2) in this eta-phi region over a given threshold.
  7. TAU Count
    This 12-bit count is broken up into 6 2-bit sections, each corresponding to the number of TAU objects (0,1,2,>2) in this eta-phi region. Tau objects are required to pass two separate cuts:
    1. Tau isolation ratio (Et(2x2)/Et(4x4)) over a threshold
    2. For the Jet object closest in phi to the above isolated Tau, Et(jet) over a threshold
  8. EM+H Sum
    Et = Sum(eta=0-39,phi=0-9) [Et(EM-TT) + Et(H-TT)]
    Ex = Sum(eta=0-39,phi=0-9) [Et(EM-TT) + Et(H-TT)] cos(theta)
    Ex = Sum(eta=0-39,phi=0-9) [Et(EM-TT) + Et(H-TT)] sin(theta)
  9. BC Or
    OR of Bunch crossing numbers received by TAB chips 0-9 from the ADF.
  10. Sync
    The frame signal for TAB-to-GAB data transfer. Goes high on the LSB of each 12-bit transfer.
  11. Valid
    Goes high on run start (1st TURN signal after an INIT). Enables data capture at the GAB input (sync memory). Only bit 47 is used for this.
  12. SCL BC
    Bunch Crossing number calculated internally by TAB.
  13. SCL TURN
    Turn number calculated internally by TAB (only lowest 12 bits of 16 are transmitted).
  14. EM Iso
    For each eta region (S,C,N) a 4 bits are sent indicating whether any EM object at any threshold passes the isolation requirement at that phi (5,4,3,2). See the algorithms section for more details on EM Isolation.
  15. Parity
    Vertical Parity of words 0-47.
  16. Status
    Normal status = 0x901
Bits Definition
11 OR of valid data bits from TAB chips 0-9
10 NOT (AND of valid data bits from TAB chips 0-9)
09 =0 if OR of all BCs received from ADF on TAB chips 0-9 is equal to the internally calculated BC
=1 otherwise
08 =1 if all PLLs locked
07..00 OR of status words from TAB chips 0-9

TAB to GAB Bit Stream Multiplexing

  Bit-Stream in Cycle
Cable Pair 0 1 2 3 4 5 6
0 0 1 2 3 4 5 6
1 7 8 9 10 11 12 13
2 14 15 16 17 18 19 20
clk Clock
3 21 22 23 24 25 26 27
4 28 29 30 31 32 33 34
5 35 36 37 38 39 40 41
6 42 43 44 45 46 47 48

Notes:

  1. Stratix LVDS reference ???
  2. The same cable/connector as used in ADF-to-TAB data transmission is employed in TAB-to-GAB transmission. A diagram of the pinouts of the connector can be found here. Refer to:

TAB to GAB Data Transmission Speed

LVDS Clock Speed

Data Transmission Rate