Tektronix 7834

Theory of Operation-7834
Device

Symbol
LO-state
indicator
Edge
symbol
Triggered
(toggle)
Flip-Flop
T
0
X
TABLE 3-1 (cont)
Description
A small circle at
the input or
output of a symbol
indicates that
the LO state is the
significant state .
Absence of the circle
indicates that
the HI state is the significant state
.
Two examples follow :
AND gate with LO-state indicator 1
at the A input .
The output of this gate is
H I if and
only if the A input
is
LO
and the B
input is H I .
OR gate with LO-state
indicator at
the A input :
The output of this gate is HI if
either the A input is LO or the B
input is HI .
Normally superimposed on an input
line to a logic symbol . Indicates
that this input (usually the trigger
input of a flip-flop) responds to the
indicated transition of the applied
signal .
A bistable device with one
input
and two outputs (either or both
outputs
may be used) . When
trig-
gered, the outputs change
from one
stable state to the other
stable state
with each trigger . The outputs are
complementary (i .e ., when one out-
put is HI the other is LO) . The edge
symbol on the trigger (T) input
may be of either
polarity depending
on the device .
Input/Output Table
Input Output
Condition
Condition
before trigger
after trigger
pulse
pulse