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kCall
Informal
A kCall (k>0) has k+1 input terminals
a_i (0<=i<k) and b,
and k+1 output terminals
c and d_i (0<=i<k).
A signal appearing on either of the a_i terminals will cause a signal
to be produced at terminal c.
The combination of a signal at terminal a_i and
terminal b will cause a signal to be produced at terminal d_i.
The environment must guarantee mutual exclusion of the a_iinputs.
Schematic diagram
for a kCall:
[ZoomFIG]
We provide XDI specifications for the 3call:
Specification in XDI model.
the 4call:
Specification in XDI model.
and the 5call:
Specification in XDI model.
(Not available for general k.)
Parameterized definitions are not possible in VERDECT, but this sketch gives
the general idea:
Specification in Verdect:
define CALL[k]( a0?, ..., a(k1)?, b?, c!, d0!, ..., d(k1)! ) =
pref *[ (a0?  ...  a(k1)?); c! ]
 pref *[ (a0?  b?); d0!
 ...
 (a(k1)?  b?); d(k1)!
]
end
Also available through this link
Pure DI Algebra does not allow a generalized specification. The following
specification therefore needs instantiation before interpretation:
Specification in DI Algebra:
CALL(k) = [(,i:0<= i < k: a_k? > c!; C(i,k))]
C(i,k) = [ b? > d_i!; CALL(k), (,j: 0<= j < k: a_j? > a_j? > CHAOS)]
Also available through this link
We provide DI Algebra specifications for
As an example we give the
XDI Report for the case k=3.
The roles of subscripts i can be permuted
(on a_i and d_i simultaneously).
The kCall satisfies Rules Y' and Z^out, but not Z^inp
(choice between a_i inputs).
DI Decompositions
 A 2Call is a Call.

A kCall can be implemented with
k Fork,
a kMerge and
a kLatch (equ):
[ZoomFIG]
 An (m+n)Call can be implemented with
an mCall and an (n+1)Call (equ):
[ZoomFIG]
As an example we composed two 5calls to form a 9call.
The Ludwig verification script of this implementation..
Using Boolean Gates
No information available
Using Transistors
No information available
The kCall can be generalized to an
mxnDecision Call,
which merges m mutually exclusive inputs and
also combines them with n mutually exclusive inputs,
reporting the combination as one among mn outputs.
A kCall is
an mxnDecisionWait with n=1.
No information available
Last modified at Fri Nov 20 10:11:40 1998
Encyclopaedia of DelayInsensitive Systems
Copyright © 19951998
Tom Verhoeff /
Tom.Verhoeff@acm.org