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tlreory
and Schematics- -Model 5\559e'
Tab1e
8-2. Logic
Symbol-s
(Cont'd)
INPUTS
-
lnputs are
located
on the left
side
of the symbol and
are
affected by their dependency notation'
Common
control inputs are located in the control block
and
control the inputs/outputs to the array
elements
according to the dependency
notation.
lnputs
to the array elements are tocated
with
the correspondin
g
ar(ay element
with
the
least
siQnif
icant element
closest to the
control
block.
OUTPUTS
- Outputs
are
located on
the right side of the symbol
and are
effected by their dependency notation'
Common
control outputs are located in the control
block.
Outputs
of
array
elements are
located
in the
corresponding
array element with the
least
significant
bit closest to
the
control
block.
CHlp
FUNCTION
- The
labels
for chip functions
are
defined,
i.e., CTB
- counter,
MUX
-
multiplexer.
DEPENDENCY NOTATION
Dependency
notation
is
always
read
from left to right
relative
to the symbol's orientation.
Dependency
notation indicates the relationship between inputs, outputs,
or inputs
and
outputs.
Signals having
a
common relationship
will
have
a
common number, i.e.,
C7
and 7D....C7
controls D.
Dependency notation
2,g,5,6+/1,C7
is
read
as
when
2 and 3
and
5 and 6 are
true, the input
will
cause
the counter
to increment
by one
count....or
(/) the input
(C7)
will control the loading of the input
value (7D)
into the
D
flip-flops.
The
following types of
dependencies are defined:
AND (G), OR (V), and Negate
(N)
denote Boolean
relationship between inputs and outputs
in
any
combination.
lnterconnection (Z) indicates connections inside
the symbol.
Control (C)
identif ies
a
timing
input or
a
clock
input
of
a
sequentialelement
and
indicates which inputs
are
controlled by
it.
Set (S)
and
Reset (R)
specify
the internal logic
states
(outputs) of
an
RS
bistable element when the
R
or
S
input
stands
at its internal
1 state.
Enable
(EN)
identif ies an
enable
input and
indicates
which
inputs and outputs
are
controlled
by
it
(which
outputs can
be
in their
high
impedance
state).
Mode
(M) identifies
an
input that selects the mode of operation of
an
element and indicates
the
inputs
and
outputs depending on that
mode.
Address
(A) identifies
the address inputs.
Transmission (X) identifies
bi-directional inputs
and
transmission
input
is true.
outputs
that are connected together when
the
DEPENDENCY
NOTATION
SYMBOLS
b.
C.
d.
e.
I
h.
A
EN
G
M
Address (selects
inputs/outputs) (indicates binary
range)
Control (permits
action)
Enable
(
permits action)
AND
(permits
action)
Mode (selects action)
N
R
S
Z
x
Negate
(compliments
state)
Reset
lnput
Set
lnput
OR
(permits
action)
lnterconnection
Transmission
LS-08-09-82
-
2
8-tz
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