Level 2 data format
The Level 2 - SVT interface board receives
fitted track packets
from the Track Fitter (TF)
and stores them for readout.
Also a subset of the TF information is sent to the
Level 2 alpha processsors.
Each track data is sent in two 32-bits words.
Each transfer from the L2 interface to the L2 processors is a 128-bit trasnfer on the L2 Magic Bus, thus 2 tracks are sent in each Magic Bus transaction.
Data structure for each track
| 31 | 30 |
29 | 28 |
27 | 26 |
25 | 24 |
23 | 22 |
21 | 20 |
19 | 18 |
17 | 16 |
15 | 14 |
13 | 12 |
11 | 10 |
9 | 8 |
7 | 6 |
5 | 4 |
3 | 2 |
1 | 0 |
| FQ<2..0> |
d(10) |
z(6) |
phi(13)
|
| EE |
FQ<3> |
ER |
track number(9) |
chi square(11) |
c(9) |
- d, z, phi, track number, chi square and c are a copy of the same
paramter sent by the Track Fitter and described in the
track page.
- curvature (c) and impact parameter (d) the leftmost bit
is the sign bit.
- ER is the TF ERror summary bit (bit 11 of the Track Fitter
status in the last word of the TF
track packet).
- The 4 FQ bits are the Track Fitter fit quality code, i.e. the 4 least
significant bits of the TF status word in the last word of each TF
output packet, see the
track page.
- The EE bit (bit 31 in second word)is set in
the last track of the current event.
BACK to the
SVT data words format page