4516 PROGRAMMABLE LOGIC UNIT


FAST, FIRSTLEVEL TRIGGER PROCESSING


The LeCroy ECLine programmable logic module family includes logic delays, Boolean logic and other functions vital for high speed trigger systems. It also includes fast table lookup permitting pre-programmed responses to digital data. Functions are performed in only a few tens of nanoseconds, permitting data to be screened prior to recording and increasing the sensitivity of the experiment.

FUNCTIONAL DESCRIPTION

LeCroy's ECLine programmable logic modules are designed to quickly characterize data so that a decision can be made for further processing. For example, discriminators are employed to ensure that analog signals are of sufficient amplitude to be interesting, and to provide logic outputs of fixed duration. This stage is then followed by a coincidence latch which records the pattern of "interesting signals" that occur within the same time window. The first level trigger modules ensure that specific combinations of signals have occurred. (Information on discrimina tors and latches may be found on other ECLine data sheets.)

This first stage of data handling can then either reject the event as uninteresting, or can pass data on for further processing. The more sophisticated line of ECLine Data Handling modules include data conversion, arithmetic operations, fast "do loop" type operations, and specialized pattern recognition. Information on LeCroy data handling modules may be found on the data handlers technical data sheet. All functions are programmable to provide complete computer control of the triggering and data acquisition systems.

The LeCroy ECLine modules are compatible with several systems using ECL bus such as the FERA (Fast Encoding and Readout ADC) system, 1821 based FASTBUS systems as well as with the PCOS 3 System. These systems can interface to VME via the LeCroy VME Dual Port Memory Model 1190.

Model 4516 Programmable Logic Unit


The 4516 is a 3-fold AND/OR logic unit. Each of the 16 channels has three inputs (A, B and C). All channels have a front-panel output that is one of the Boolean combinations: (A·B·C), (A+B)·C, (A·B)+C, or (A+B)+C. The choice of logical function, AND (·) or OR (+), is set for all channels by two switches. These switches are set either by rear-panel manual switch settings or by CAMAC command.

The 150 MHz speed of 4516 lends great versatility to this simple module. It can be used as a front-end AND/OR logic module, or an integral component in a higher level trigger processor.

Model 4516 Logic Diagram

SPECIFICATIONS

Model 4516 Programmable Logic Unit


Inputs: 16 sets of three inputs, 110 ohm ±5% (high impedance by removal of socketed terminators), DC -coupled, on 34-pin headers, for ECL signals, minimum 2 nsec rise time. Maximum rate 150 MHz.

Veto: One rear-panel Lemo connector, 50 ohm impedance. Requires -600 mV signal. Permits gating of outputs, including OR outputs. Must overlap coincidence for the three front-panel inputs by > 5nsec.

Outputs: 16, one per set of three inputs, complementary ECL logic levels on 34-pin header.

OR Out: Two, one for OR of first 8 outputs, one for second 8 outputs (factory option permits OR'ing of all 16 outputs).

Double Pulse Resolution: 5 nsec at minimum input width.

Coincidence Width: > 3.5 nsec determined by input pulse width.

Input-Output Delay: A or B to OUT by 11 nsec typical; A or B to OR by 12 nsec, typical; C to OUT by 8 nsec, typical; C to OR by 9 nsec, typical; VETO to OUT by 8 nsec, typical; VETO to OR by 6 nsec, typical.

Power: 50 mA at +6 V; 1.25 A at -6 V (7.8 W total).


CAMAC COMMANDS

Model 4516 Programmable Logic Unit


CAMAC COMMANDS

X: An X response is generated when a valid N, A, F command is recognized.

Z: Sets all channels to OR Mode.

CAMAC FUNCTION CODES

F(26)·A(0): Sets all C0s to AND Mode.

F(24)·A(0): Sets all C0s to OR Mode.

F(26)·A(1): Sets all C1s to AND Mode.

F(24)·A(1): Sets all C1s to OR Mode.

F(27)·A(0): Gives a Q response if C0 switch is in AND Mode.

F(27)·A(1): Gives a Q response if C1 switch is in AND Mode.

Copyright© September 1995. LeCroy is a registered trademark of LeCroy Corporation. All rights reserved. Information in this publicaction supersedes all earlier versions.