ECL Data Adapter Module (EDA) PD-31

This gives the specs for the ECL Data to DYC3 interface being made for E831 and E835. The purpose of the module is to allow a PCOS III 2738, an SCC or a FERA 4301 controller to send data to the DYC3 without further external circuitry. There may be other modules which act as ECL data sources; they may need some extra user provided circuitry to be able to feed a DYC3. The only control the DYC3 exercises on its data sources is to (try to) inhibit the sending of data from a new event if the input data fifo's are half (or more) full. The user needs to ensure that the data sources do not send data when the DYC3 cannot receive it (them). For the FERA 4301 controller data flow is controlled with the REN signal; for the PCOS controller this is done with the ACK signal. Users are expected to ensure that their sources are properly inhibited. (very British)

Each EDA requires its own DYC3. There is no token passing scheme to allow several EDA's to feed one DYC3.

INPUTS:

From Data Source:

ECL Data: 16 pairs of Differential ECL received with 10116 and terminated in 56 ohms each side to a common line connected in sets of three input pairs with a 0.1 uf capacitor to ground.

DS (Data Strobe) - Differential ECL and NIM terminated in 51 ohms (note 1)

BUSY - NIM terminated in 51 ohms (= PCOS BUSY or REQ from 4301)

PASS - Differential ECL (end of data from 4301)

START - Differential ECL (Header signal)

DONE - Differential ECL (End of record)

RESET - Differential ECL, pins 13, 14 (pin pair below DS). Used to reset the module in the event of a DONE signal not following a START signal.

From DYC3:

REN - Differential ECL (readout enable)

OUTPUTS:

To DYC3:

Data to DYC3: 16 pairs of Single-sided ECL, (+) = signal, (-) = ground.

FERA Control Bus to DYC3 - including

WST (write-strobe) to DYC - formed from Data Strobe

REQ (formed from BUSY or START)

To Source:

REN to FERA 4301 (differential ECL)

ACK to PCOS 2738 (NIM)

Possible styles:

Camac, 1 U Chassis.

note 1) since the speed of the cable that carries the NIM signal will typically be faster than the data cable (difference of 0.5ns/foot) some care needs to be taken by the users for runs of 20 ft or more to ensure that the data strobe is timed properly w.r.t. the data.