Glossary
The window in flowHDL or blockHDL that the user is currently
working with. The active window
will have a highlighted title bar and it will always appear to be in front of
all other windows.
A symbolic name for an expression.
A device that evaluates pending requests from agents for
access to a common resource and grants this resource to a master based on a
specific algorithm.
See transition
arc
A hardware construct which combines the properties of a latch
and a register. During states in
which active assignments take place, the signal behaves asynchronously. In other states, the last value if
signal is held by a register.
A simulation model described in highly abstract terms and
bearing no implementation details.
a signal that can be both read and written to.
A collection of read/write signals that can be driven by
multiple state machines. The signal
must be of MVL type and presently,
the global "z" is assigned "1" or "0," and a contention yields "x."
A built-in self test.
a graphical construct which represents structural components
of a system.
a diagram, composed of interconnected blocks, which represents
the structure of a digital system.
A built-ina write signal that can be
read by the source block.
A string of text in a flowdiagram which represents a
collection of signals in a digital system.
A single signal of a bus.
Two or more consecutive signals of a bus.
The area in flowHDL used to create, edit, and display
flowdiagrams.
A flowdiagram object which represents a multi-way decision in
the control flow of a digital system based on the value of a selected input,
internal, or internal output bus.
a command directing the user to press the left mouse
button.
A signal defined for the purpose of synchronizing the actions
of a system component, so that the behavior is reliable, repeatable, and
stable. Clocks controling the data
path vs. the control path of a design thread are represented separately in
flowHDL.
Actions that may occur in parallel at the same instance of
time. Concurrent threads operate
independently from each other.
A flowdiagram symbol which represents a Boolean decision in
the control flow of a digital system.
A flowdiagram symbol which represents the placement of actions
in a digital system, where activation is dependent on both the present state and
specified input signals.
A symbolic name for a hard-coded numerical value.
The portion of a design thread, primarially represented by
graphical objects and transitions, which describes the sequencing of a design’s
actions.
A temporary file that contains the most recent text, object,
or group of objects that were cut or copied within the current workspace.
Neither flowHDL nor blockHDL will not retain the copy buffer when you move from
one flowHDL or blockHDL file to another.
The portion of a design thread, primarially represented by
expressions, which describes its actions.
A condition where two separate threads acquire a target
resource simultaneously, but the action to be taken by each thread is blocked by
the other.
A window in flowHDL or blockHDL that can be used to
communicate with the application through text entry and option selection.
press the left mouse button twice quickly.
Steps in the design process that take place after the use of
flowHDL or blockHDL.
Place the mouse pointer so that it touches an object and hold
down the left mouse button while moving the mouse. (Release the left mouse button when you
have reached the desired location.)
The area of the canvas used to create, edit, and display
blockdiagrams or flowdiagrams.
A property of a bus representing an abstract hardware
construct.
Datapath reset and control path reset events.
The data types, operators, and macro functions associated with
a flowdiagram object.
flowHDL's graphical representation of a digital design, based
from the standpoint of a time-based sequencing of control and data path actions
that specify the behavior of a digital circuit. Based on ASM chart.
Returning a control thread to the initial state when an
exception is encountered.
A button on a
computer keyboard (labeled f1, f2, f3,
etc.), usually located along the top or in a group at the right of the
keyboard, that activates some function when pressed alone or in conjunction with
other keys.
A gated expression including a specific clock which is
connected to and triggers the clock input of either a data or control path
register.
A gated expression which includes a specific clock which is
connected to and actibates the common reset or preset of a data or control path
register.
(a.k.a. marquee)
an image that appears on the screen when you drag an object from one
location to another. The ghost
image is usually the same shape and color as the object, but contains no
associated text.
the introduction of a parent block for one or more blocks.
An action performed by the user to set a portion of text, an
object or a group of objects apart from the other text and objects in the
drawing area or dialog box.
see mnemonic
a read only signal.
A collection of read only external signals entering the
system.
A sub-lowdiagram symbol that represents a connection to
one or more source objects located in the main flowdiagram that specifies how a
subflowdiagram segment is entered.
A flowdiagram object which is the target of an output label,
showing continuity of a visually disconnected transition arc.
create an instance of
a parsed-in design component in blockHDL
A collection of read/write signals within the system, where
all threads can read the signals but only one thread can write the signals.
A collection of output signals that can be read by all threads
in the system and are also a system output.
a block diagram symbol which allows you to specify the routing
of individual bits of a net.
A sequential device that changes its output, at any time, in
response to input changes.
The stretch of time between the start of an operation and its
completion.
A condition where a process loop infinitely waits for a signal
which never becomes true, causing the system to become congested (a.k.a.
indefinite ping-pong, starvation).
A master’s ability to exclusively own a resource
(during a set time interval) and lock out any competing agent from access.
A behavioral implementation of a standard RTL function.
a square symbol appearing at the left of an item in a pulldown
menu indicating that that item is currently activated.
see ghost image
A list of topics visible across the top of flowHDL’s and
blockHDL's main window. Clicking on
one of these topics provides a list of sub-menu items.that can be activated by
clicking on them.
The state of a bi-stable device when the input transitions
violate setup and hold time restrictions occurring during a narrow timing
window. The bi-stable flip-flop can
enter a balanced transitory state called “meta-stable.”
an underlined letter within a menu that can be used to
activate that menu item through the keyboard, i.e., a “hot key”.
A property of a signal that indicates its direction in the
data path.
A thread in a flowHDL design designated as an integral portion
of the model. Each design must have
at least one model thread.
a small object on the screen which follows the movement of the
mouse and indicates its current position.
The mouse pointer appears as an arrow by default.
a line specifying the signal paths between ports of different
blocks in the block diagram and between ports and pins that cross levels in the
block herarchy.
Any flowdiagram or blockdiagram symbol which appears
graphically within flowHDL or blockHDL.
a write only signal.
A collection of write only signals that leave the system. Each thread can have an independent
output bus, but other threads cannot read that output.
A sub-flowdiagram symbol that represents a connection to a
target object located in the main flowdiagram and specifies a sub-flowdiagram
exit point.
A flowdiagram object which is the source of an output label,
showing continuity of a visually disconnected transition arc.
To copy new information over existing information, erasing the
existing information.
The vertical column of buttons to the left of the drawing area
that is used to place objects on the drawing area.
extract port information from an HDL description.
a stylized arrow directed into the block, out of the block, or
in both directions which connects blocks in one level of the hierarchy to blocks
at a higher level.
Partitioning hardware storage into parallel blocks of
registers so that multiple algorithmic solution steps can be performed at the
same time.
a stylized arrow directed into the block, out of the block, or
in both directions which connects blocks within one level of the hierarchy.
a sub-menu, accessed by clicking on a main menu item,
containing a list of flowHDL or
blockHDL functions that can be activated by clicking on them.
a window in blockHDL that can be used to view underlying rules
within blockHDL. The user cannot
interact with the application through this window.
a small character next to a string of text in a dialog box
that is used to activate or deactivate an option by clicking on it. The button appears darkened or
"depressed" when activated, lightened or "undepressed" when
deactivated.
See synchronous
register or asynchronous register
register transfer
level (RTL)
model | |
A simulation model, described with basic procedural constructs
and functional operators, which may be targeted for an automated synthesis
tool.
A signal or expression that resets all registers in a thread
and initiates that thread. This
term is also used for a signal attached to the initial state in the control flow
of a thread.
The ability to recall and use a resource entity (a.k.a.,
library lookup).
to view hidden text or graphics in a window through use of the
scroll bar.
a graphical feature appearing along the right or the bottom of
a window used to view hidden text or graphics in that window. A scroll bar automatically appears when
the text or graphical entry area in the window increases in size beyond the
boundaries of the window.
A flag used as an aide in locking a
resource.
A logical partition of a flowdiagram, equivalent to a sheet of
paper.
The act of applying input to a system to gain output
response.
An object in flowHDL or blockHDL that is connected to another o
bject (target object) through use of a transition arc.
A flowdiagram object representing a state of a digital
system.
The portion of a flowdiagram which occurs within one clock
cycle, represented by a state and all objects and transitions that occur after
that state and before the next state.
A bar located in
a flowHDL or blockHDL drawing area that displays information about the currently
active mode and options available within that mode, or a currently selected
object.
A netlist representation of a device that consists of
instantiated components and their interconnections.
A flowdiagram
thread that is not an integral part of the design model. Stub threads in a design may be
translated separately from the rest of the model.
A special case of a sheet which is subordinate to a normal
sheet and can be instantiated in multiple parts of a flowdiagram thread.
A timing constraint on concurrent actions, causing some theads
to wait until the current thread is finished when shared data is written to by a
single thread at a time.
A sequential element which samples its input upon receiving an
active control path clock edge to reflect the input to the output after a
specified delay.
An object in flowHDL or blockHDL to which another object
(source object) is connected through use of a transition arc.
to end the flowHDL or blockHDL application.
A thread containing signals used to test the design. The test harness may be translated
separately from the rest of the design, and used as simulation input.
a box that, when selected by clicking on it, allows you to
enter a string of text.
A statically ordered sequence of states which may act
concurrently with other flowdiagram threads in the same flowHDL file.
a bar located at the top of a window that displays the title
of that window.
An item that has only two options, usually "on" and "off."
A flowdiagram object, represented as a line with an arrowhead,
which traces the control flow from one object to another.
The property of a signal that denotes its data values (e.g.,
binary, enumerated).
the replacement of a selected block by its child blocks.
To increase or decrease the size of the unit used as a scale
in the wave viewer.
a self-contained area within an application that contains
inter-related information.
A signal which has values assigned asynchronously and which is
assigned its default value if a value is not explicitly assigned by the
user.
To increase or decrease the magnification of graphical objects
within a window.