LeCroy's new ECLine Model 4508, a standard CAMAC module, consists of two independent 8- input logic units, each able to perform any kind of logical operation on the eight inputs. Each section provides eight outputs. The circuit is programmable so that each output can correspond to a different logical combination of the inputs. There is no limitation on the complexity of the logical function which can be accomplished on the eight inputs. The logical configuration can be either an AND and OR, an exclusive OR, an Inhibit, a multiplicity function, or any combination of these functions as well. But the usefulness of this circuit goes much further. It finds application anywhere a logical problem exists. Other examples of useful applications are eight-bit output register (word generator), adder, colinearity, etc.
As soon as a strobe pulse arrives, the input pattern is stored on registers. These can be read. and reset. reset through normal CAMAC operations, or they can be reset by an external fast
The front-panel 17-pair flat cable connectors are conveniently compatible for interconnection with LeCroy ECLine discriminators, scalers, and other logic units.
SPECIFICATIONS
INPUT CHARACTERISTICS
Number of Channels: 2, identical.
Inputs: Eight, in a single 2 x 17 pin connector; 110 Ohm input impedance (op-
tionally high impedance available); accept differential ECL levels.
Input Width: Minimum input pulse width or overlap to produce outputs, 10 nsec;
maximum width D.C.
Maximum Rate: >65 MHz.
Strobe Input: One per section; Lemo-type connector; 50 Ohm input impedance; a
negative NIM logic pulse enables; minimum width to enable, 5 nsec;
maximum frequency, 65 MHz; the strobe pulse must precede the
input pulses by 2 nsec to achieve exact time coincidence; a strobe
pulse must always be followed by a clear pulse or by a CAMAC reset
function or command.
Clear Input: One per section; Lemo-type connector; 50 Ohm input impedance; a
negative NIM logic pulse clears pattern registers when operating in
"overlap", "shaped" or "continuous" mode, resets output levels
when operating in "continuous" mode; minimum width to clear, 5 nsec.
OUTPUT CHARACTERISTICS
Outputs: Eight per channel (single 2 x 17 pin connector); complementary ECL
levels.
Output Width: Depends on the output operation mode. In the "shaped" mode, the
output width can be adjusted between <5 nsec and >100 nsec via a
front-panel potentiometer common to each eight outputs. In the "over-
lap" mode, the output width is equal to the input width or coincidence
overlap. In the "continuous" mode, the outputs, enabled by the strobe
pulse, are frozen in their dynamic state until the next external fast clear
or CAMAC reset function or command.
Syncro Output: One per section; Lemo-type connector; high output impedance (current
source). When terminated into 50 Ohm, NIM levels are generated. The
syncro output reproduces the strobe pulse after a constant delay of (17
+/- 1) nsec. Pulse width equals the width of the normal outputs. This
output can be used, for instance, as a strobe for subsequent units or as
a clear for the unit itself.
GENERAL
Strobe-Clear LED: A front-panel LED fires in conjunction with any strobe pulse and until
the next clear.
Propagation Delay: (17 +/- 3) nsec in "overlap" mode; in "shaped" or "continuous" mode,
the delay is fixed by the strobe timing; delay between strobe and
output, (21 +/- 1) nsec independent of the chosen logical operation.
Operation Modes: A front-panel switch, one per section, allows choice of one of the
following three output operation modes, common to all outputs of a
section:
Overlap (OVL)-The output pulse width is determined by the input
pulse widths (OR function) or by the input pulse overlap (for other
functions).
Shaped (SHP)-The output pulse, which includes an AND with the
strobe pulse, is reshaped. The output pulse width is adjustable in the
range 5-100 nsec through a potentiometer (one per section) on the front
panel.
Continuous (CNT)-The outputs, which include an AND with the strobe
pulse, are frozen in their dynamic state until an external fast clear or a
CAMAC C, Z, F9, or F2 occurs. This output mode is particularly con-
venient to avoid timing problems.
Input Pattern: As soon as a strobe pulse is applied, the input pulse configuration is
stored on registers which can be read afterwards by CAMAC. This is
true for any of the output modes. This very useful facility allows an off-
line reconstruction of the trigger.
In order to clear the pattern registers, the strobe pulse has to be
followed by a clear pulse or by a CAMAC C, Z, F9, or F2.
Logical Functions Accomplished: Each section of the module, after suitable programming
, is able to perform any kind of logical operation on the eight inputs. The eight
outputs are separately programmable so that each output can corre-
spond to a different logical operation on the inputs. Or, at the other
extreme, all outputs can have the same meaning if higher fan-out is
required.
Programming: Each 4508 section contains a 256-word x 8-bit memory, which must be
programmed with 256 consecutive steps to indicate which of these 256
possible configurations of the 8 inputs will give or not give an output.
CAMAC COMMANDS
AND FUNCTIONS
Z or C: Word 0 is addressed in the memories in both sections; pattern registers
are cleared.
X: An X= 1 response is generated for any valid CAMAC function (F) shown
below.
Q: A Q=l response is generated for any valid CAMAC function, except
when the memory addresses overflow. (This latter feature permits one
to recognize when the reading or the loading of a memory has been
completed.)
FO: FO-AO, read first section 8-bit input pattern; FO-A1, read second section
8-bit input pattern; FO-A2, read first section memory content at the
given address; the memory content is displayed on read lines Rl-R8,
the given address on read lines R9-Rl6. FO-A3, as before but for the
second section.
F2: F2-AO, read first section 8-bit pattern and reset at S2; reset output
levels when operating in continuous mode; F2-A1, same as F2-A0, but
for the second section. F2-A2, read first section memory content at the
given address (as for FO-A2) and increment address by one at S2;
F2-A3, same as F2-A2, but for the second section.
F9: F9-A0, clear first section pattern; reset first section output levels when
operating in continuous mode; F9-A1, as above, but for the second
section; F9-A2 or F9-A3, reset memory address in both sections.
F16: F16-A0, load first section memory content at the given address; data
have to be sent on write lines W1-W8; F1 6-Al, as above, but for the
second section. Fl6-A2, random access to the first section memory at
S1 (the selected address has to be sent on write lines W9-Wl6); load
memory content with data present on W1-W8, at the selected address,
at S2. Fl6-A3, same as above, but for the second section.
F18: F18-AO, load first section memory content, at the given address, with
data present on Wl-W8, at Sl; increment address by 1 at S2. F18-Al,
as above, but for the second section. Fl8-A2 or Fl8-A3, random
access to both section memories (the selected address has to be sent
on write lines W9-Wl6).