Symbols Inside The Outline - HP 5334B Service Manual

Table 8-4. Symbols Inside the Outline
HP 5334B
-
Service Manual
8-11
Symbol
lt-
AD
a t -
"
ol-
' '
VF
I
D ,
+EN
J.
K. R .
S. T
- i ~
4 - m 4 - m
A + r n
+-m
4
: ]
4 ~ ~ = 1 5
C T = ~
dl
" 1 ° F
Description
Postponed output (of a pulse-triggered flip-flop). The output changes when input in-
itiating change (e.g., a C input) returns to its initial external state or level.
Bi-threshold input (input with hysteresis)
NPN open-collector or similar output that can supply a relatively low-impedance L
level when not turned off. Requires external pull-up. Capable of positive-logic wired-
AND connection.
Passive-pull-up output is similar to NPN open-collector output but is supplemented
with a built-in passive pull-up.
NPN open-emitter or similar output that can supply a relatively low-impedance H
level when not turned off. Requires external pulldown. Capable of positive-logic
wired-OR connection.
Passive-pull-down output is similar to NPN open-emitter output but is supplemented
with a built-in passive pull-down.
3-state output
Output with more than usual output capability (symbol is oriented in the direction of
signal flow).
Enable input
When at its internal 1-state, all outputs are enabled.
When at its internal 0-state, open-collector and open-emitter outputs
are off, 3-state outputs are at normally defined internal logic states and
at external high-impedance state, and all other outputs (e.g., totem-
poles) are at the internal 0-state.
Usual meanings associated with flip-flops (e.g., R
=
reset, T
=
toggle).
Data input to a storage element equivalent to:
Shift right (left) inputs, m
=
1, 2,
3 etc. If m
=
1,
it is usually not shown.
Counting up (down) inputs, m
=
1,
2,
3 etc. If m
=
1, it is usually not shown.
Binary grouping. m is highest power of
2.
The contents-setting input, when active, causes the content of a register to take on
the indicative value.
The content output is acftive if the content of the register is as indicated.
Input line grouping
. .
.
indicates two or more terminals used to implement a single
logic input.
e.g., The paired expander inputs of SN7450.
- X
41~
Fixed-state output always stands at its internal
1
state. For example, see SN74185.