Initialization/Synchronization of ADF to TAB Data Transfer

updated: 25-May-04

Index

Initialization of Data Transfer

Data transfer is (re)initiated between the ADFs and TABs by means of an SCL Init. The following is how the TAB expects this procedure to go.A diagram of this timing is shown below
  1. Init received separately by ADFs and TABs
    o INIT_SECTION --> hi
    o ADFs stop sending Data and Frames
  2. Boards acknowledge and perform initialization
    o INIT-ACK --> hi
  3. ADF system and TAB system signal that they've finished their init process to hub
    o INIT-ACK --> lo
  4. After INIT_ACK signals from all geographic sections have been dropped the hub deasserts INIT_SECTION
    o INIT_SECTION --> lo
  5. At the 1st turn indicator (FIRST_PERIOD) after INIT_SECTION goes lo, the ADFs start sending Data and Frames
    o FIRST_PERIOD --> hi
    o ADF sends Frame and Data
    o TAB starts data resymchronizing logic

Initialization Timing Diagram



(pdf version here)

Retiming ADF Data at the TABs

ADF data, arriving from the Channel Link deserializer, is retimed to the TABs clock using the logic shown in the diagram below.



(pdf version here)