ROAD-HIT packet format


As the Hit Buffer (HB) receives roads from the Associative Memory Sequencer (AMS), it sends the needed data to the Track Fitter(s) (TF).
For each road received the HB forms a Road-Hit packet that contains all the hits that belong to that road (both SVX hits and XFT tracks) ordered by layer (0 first, 5 (XFT) last). If one layer has more then one hits, they are all sent in the same order as they have been received by the HB before the next layer date are sent. If a layer has no hits, it is skipped.
The XFT track is sent as two consecutive data words both with EP=0, the TF will use the layer info in the first such word to know how to deal with both.
The packet is closed by a word containg the road data received from the AMS, and with EP=1.

Packet structure

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
HD DS 0 0 Layer(0..4) SVX hit
HD DS 0 0 Layer(0..4) SVX hit
HD DS 0 0 Layer(0..4) SVX hit
HD DS 0 0 . . . . . .
HD DS 0 0 5 XTF 1st word
HD DS 0 0 XTF 2nd word
HD DS 0 0 5 . . .
HD DS 0 0 . . .
HD DS 0 1 road


The format (bits 0-20 allocation) for the various words is in the HITS, ROADS and XTF_tracks pages.
The format of the data for the tracks (if any) fitted from data in this packet is in the TRACK page


BACK to the SVT data words format page