The Model 2373 is a 1024 K-bit dual-ported random access memory based on the LeCroy Model 2372 but with 16 times the memory thereby allowing the 16 bit input address word to generate a 16 bit output word. Packaged in a single-width CAMAC module, the Memory Lookup Module (MLU) has a 45 nsec cycle time making it a very desirable module for complex functions required of trigger logic or high speed data processing.

In normal use, the MLU is first downloaded with the required trigger data and then verified via CAMAC. This information, which defines the function of the MLU, is accessed via the two 16 bit front panel Data-in and Data-Out connectors for real time applications.

The function of the MLU is user defined to meet the application. Virtually any function may be defined: angle logic or clusterized track multiplicity are examples of complex trigger functions. When used as a trigger processor element, the MLU may be used for any operation which is a one-to-one mapping. In conjunction with an ADC, the MLU can be loaded with the calibration to energy. The MLU can also be - loaded with a digital comparator function or any arithmetic calculation, e.g. summing, division, sin function, etc.

The Model 2373 has four software selectable operating modes. The Strobed Mode is the most commonly used mode. In this mode, the MLU is strobed by the ECL Input Enable signals coming from previous logic unit(s). After 45 nsec, the output "word" of the MLU becomes valid along with the four ECL Output Ready signals which may be used to strobe the output word into other ECLine type modules. The output word remains static until another Input Enable is received. Four Input Enables are provided with an Enable condition being defined as their coincidence (unused inputs are set to logical 1). This allows modules of this type to be interconnected and operate asynchronously (the slowest element controls the speed). A second mode is the Transparent Mode where the Model 2373 operates at maximum speed. This mode bypasses the latch circuitry and thus provides a slight speed advantage, offering a throughput time of only 40 nsec. A third mode is the Pulsed Mode. This mode is used when it is desirable to scale (count) any or all of the outputs. It insures that one and only one pulse appears at any of the 16 outputs, provided that the output bit is true for the given Input Word, when the Input Enable is made true. A forth mode allows the Model 2373 to operate identically to a Model 2372. The reason for this mode is to allow customers who have a large investment in the Model 2372 to add to their system without software changes. The Model 2373 has replaced the Model 2372 in the LeCroy product line. SPECIFICATIONS

 INPUTS:   Input Word: One 16-bit ECL input on front panel 34-pin header with 100
    ohm input impedance. Maximum rate: 22 MHz.

    Enable: Four AND'd complimentary ECL pairs on front-panel header
    into 100 ohm impedance. Unused inputs are logically true. Required
    only in Strobe or Pulse Mode where Input Word is latched on leading
    edge of Enable pulse (coincidence of Enable Inputs being used).

 OUTPUTS:   Output Word: One 1 6-bit complimentary ECL output from a front-panel
    34-pin header. In the Strobe or Pulse mode, the content of memory
    address given by the Input Word is presented 40 nsec after Input
    Enable. In the Transparent mode, the content of the addressed memory
    is presented 40 nsec after the Input Word.

    Output Ready: Four complimentary ECL pairs from a front-panel
    header. Provides Output Ready level for down-stream logic indicating a
    valid Output Word.

 OPERATING MODES:  Operating modes are set by CAMAC commands.

    TRANSPARENT: Latching is disabled. Output follows changing input-
    with minimum propagation delay (40 nsec).

    STROBE: Input Word latched on leading edge of AND of Input Enables.
    Ready appears 45 nsec after Enable.

    PULSE: Same as Strobe Mode except that all true output bits go false
    after a delay which is adjustable (20-150 nsec) via a front-panel
    potentiometer. The purpose of this mode is to allow the scaling of
    individual bits the Output Word.

    INHIBIT: Disables front-panel inputs. (Used for programming memory
    contents via computer.)

    Memory Configuration: Four 64k 4-bit Static RAMs make up the intemal
    memory allowing 16-bit x 16-bit operation. It also can be configured to
    operate as a replacement for the Model 2372 with little or no programing
    changes required (see both Model 2372 and Model 2373 Owners
    Manual). The memory in the Model 2373 has no battery back up like the
    Model 2372 and MUST be reloaded upon loss of power.

    Computer Control: Read and Write Control Register (setting Mode and
    Dimensionality); Read and Write Address Register, Read or Write data
    at address in Address Register, Read front panel input word or the
    output generated by front-panel input.

 PROPAGATION DELAY:  In the Strobe and Pulse mode, propagation delay
    is defined as the time
    between the leading edge (trailing edge for "OR" condition) of the Input
    Enable signals at the front panel and the leading edge of the Output
    Ready signals. This is factory adjusted to 45 nsec. The Output
    Word settles at least 5 nsec before a true Ready condition, thus allowing
    for proper set up time at the inputs to successive stages of
    Programmable Data Handier Modules.

    In the Transparent mode, propagation delay is defined as the time
    between the leading edge of the Input Word at the front panel and the
    leading edge of the Output Word. This time is solely a function of the
    SRAMs and is at most 40 nsec.


 GENERAL:  Maximum Rate: Transparent Mode - 25 MHz.
    All Other Modes - 22.2 MHz.

   Power Requirements: +6 V at .7 A; -6 V at 2.3 A; -6 V (via Y1 pin) at
   .8 A.
   NOTE: -6 V is required on the Y1 pin to operate. (See CAMAC pin
   allocation specifications.)