HP 437B Service Manual

HP 437B
@ Table 8-2. Schematic Diagram Notes (6 of 8)
DIGITAL SYMBOLOGY REFERENCE INFORMATION
Sequential Logic Functions
Monostable—Single
shot
multivibrator.
Output
becomes
active
when
the
input
becomes
active.
Output
remains
active
(even
if
the
input
becomes
inactive)
for
a
period
of
time
that
is
characteristic
of
the
device
and/or
circuit.
Oscillator—The output is a uniform repetitive signal which alternates between the
high and low state values. If an input is shown, then the output will be active if and
only if the input is in the active state.
Flip-Flop—Binary element with two stable states, set and reset. When the flip-flop
is set, its outputs will be in their active states. When the flip-flop is reset, its outputs
will be in their inactive states.
Toggle Input—When active, causes the flip-flop to change states.
Set Input—When active, causes the flip-flop to set.
Reset Input—When active, causes the flip-flop to reset.
J Input—Analogous to set input.
K Input—Analogous to reset input.
Data Input—Always enabled by another input (generally a C input—see Depen-
dency Notation). When the D input is dependency-enabled, a high level at D will set
the flip-flop; a low level will reset the flip-flop. Note: strictly speaking, D inputs
have no active or inactive states—they are just enabled or disabled.
Count-Up Input—When active, increments the contents (count) of a counter by
“m” counts (m is replaced with a number).
Count-Down Input—When active, decrements the contents (count) of a counter by
“m” counts (m is replaced with a number).
Shift Right (Down) Input—When active, causes the contents of a shift register to
shift to the right or down “m” places (m is replaced with a number).
Shift Left (Up) Input—When active, causes the contents of a shift register to shift to
the left or up “m” places (m is replaced with a number).
NOTE
For the four functions shown above, if m is one, it is omitted.
(Functional The following functional labels are to be used as necessary in symbol build-ups to
Labels) ensure rapid identification of device function.
SERVICE 8-11

HP 437B Specifications

General

Brand	HP
Model	437B
Category	Measuring Instruments
Language	English