IP-XACT XML Schema
Vanderlei Bonato
Sep 2008
Outline
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XML
Schema
The seven top-level IP-XACT schema
definitions
IP-XACT Docs
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What is XML?
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XML stands for EXtensible Markup
Language
XML is a markup language much like
HTML
XML was designed to carry data, not to
display data
XML tags are not predefined. You must
define your own tags
XML is designed to be self-descriptive
XML is a W3C Recommendation
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XML documents form a tree structure that starts
at "the root" and branches to "the leaves"
<bookstore>
<book category="COOKING">
<title lang="en">Everyday Italian</title>
<author>Giada De Laurentiis</author>
<year>2005</year>
<price>30.00</price>
</book>
<book category="CHILDREN">
<title lang="en">Harry Potter</title>
<author>J K. Rowling</author>
<year>2005</year>
<price>29.99</price> </bookstore>
</bookstore>
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XML Schema
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XML schema provide a means for defining the
structure, content and semantics of XML
documents
It expresses shared vocabularies and allow
machines to carry out rules made by people
It is an XML-based alternative to DTDs
(Document Type Definition)
It is also referred to as XML Schema Definition
(XSD)
It became a W3C Recommendation in May 2001
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XML Schemas are the Successors of DTDs
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XML Schemas are extensible to future
additions
XML Schemas are richer and more
powerful than DTDs
XML Schemas are written in XML
XML Schemas support data types
XML Schemas support namespaces
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What does XML Schema define?
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defines elements that can appear in a document
defines attributes that can appear in a document
defines which elements are child elements
defines the order of child elements
defines the number of child elements
defines whether an element is empty or can
include text
defines data types for elements and attributes
defines default and fixed values for elements and
attributes
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Well Formed and Valid XML
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XML with correct syntax is "Well Formed"
XML.
XML validated against a DTD is "Valid"
XML.
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IP-XACT XML Schema
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IP-XACT is a well-defined XML schema for
meta-data that documents the
characteristics of IP required for the
automation of the configuration and
integration of IP blocks
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The IP-XACT schema defined by seven top-level
schema definitions
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Bus and Abstraction Definition descriptions
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These two descriptions are referenced by
components or abstractors in their bus or
abstractor interfaces
They describe a group of ports that together
perform some function
The abstraction definition description contains
the high-level attributes of the interface,
including items such as the connection method
and indication of addressing
The bus definition contains the low-level
attributes of the interface, including items such
as the name, direction, and width of the ports
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Component description
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An IP-XACT component is the central
placeholder for the objects meta-data
Components are used to:
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describe cores (processors, co-processors,
DSPs, etc.)
peripherals (memories, DMA controllers,
timers, UART, etc.)
and buses (simple buses, multi-layer buses,
cross bars, network on chip, etc.)
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Component description
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An IP-XACT component can be of two
kinds: static or configurable.
A DE cannot change a static component.
A configurable (or parameterized)
component has configurable elements
(such as parameters) that can be
configured by the DE and these elements
may also configure the RTL or TLM model.
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Component description
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An IP-XACT component can be a
hierarchical object or a leaf object
Leaf components do not contain other IPXACT components, while hierarchical
components contain other IP-XACT subcomponents
This can be recursive by having
hierarchical components that contain
hierarchical components, etc
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Component description: interfaces
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Each IP component normally identifies one or more bus
interfaces
Bus interfaces are groups of ports that belong to an
identified bus type and an abstraction type
The purpose of the bus interface is to map the physical
ports of the component to the logical ports of the
abstraction definition
There are seven possible modes for a bus interface:
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master, slave, system interface, and may be direct or mirrored
the seventh interface mode is the monitor mode
A monitor interface can be used to connect IP into the
design for verification
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Design descriptions
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An IP-XACT design is the central placeholder for
the assembly of component objects meta-data
A design describes a list of components
referenced by this description, their
configuration, and their interconnections to each
other
The interconnections may be between interfaces
or between ports on a component
A design description is analogous to a schematic
of components
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Design descriptions
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While a design description, with referenced
components and interconnections, describes
most of the information for a design, some
information is missing, such as the exact port
names used by a bus interface
To resolve this a component description
(referred to as a hierarchical component) is
used, which contains a view with a reference to
the design description
Together, the component and referenced design
description form a complete single-level
hierarchical description
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Abstractor descriptions
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Designs that incorporate IP models using
different interface modeling styles (e.g.,
TLM and RTL modeling styles) may contain
interconnections between such component
interfaces using different abstractions of
the same bus type
An IP-XACT description may describe how
such interconnections are to be made
using a special-purpose object called an
abstractor
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Abstractor descriptions
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An abstractor is used to connect between two
different abstractions of the same bus type (e.g.,
an APB_RTL and an APB_TLM)
An abstractor shall only contain two interfaces,
which shall be of the same bus definition and
different abstraction definitions
Unlike a component, an abstractor is not
referenced from a design description, but instead
is referenced from a design configuration
description
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Generator chain descriptions
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In IP-XACT, a design flow can be represented as
a generator chain
A generator chain is an ordered sequence of
named tasks
Each named task can be represented as a single
generator or as another generator chain
This way, design flow hierarchies can be
constructed and executed from within a given DE
The DE itself is responsible for understanding the
semantics of the specified chain described in the
generator chain description
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Design configuration descriptions
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An IP-XACT design configuration is a
placeholder for additional configuration
information of a design or generator chain
description
Design configuration information is useful
when transporting designs between design
environments and automating generator
chain execution for a design, by storing
information that would otherwise have to
be re-entered by the designer
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Design configuration descriptions
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The design configuration description contains the
following configuration information:
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configurable information for parameters defined in
generators within generator chains; this information is
not referenced via the design description
the active view or current view selected for instances
in the design description
the configuration information for interconnections
between the same bus types with differing abstraction
types (i.e., abstractor reference, parameter
configuration, and view selection).
A design configuration applies to a single design,
but a design may have multiple design
configuration descriptions
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IP-XACT schemaDOC
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../IP-XACT-1.4release/schemaDOC/index.html
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IP-XACT User’s Group
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http://www.ipxact-ug.org/organization.htm
http://www.ecsiassociation.org/ecsi/main_wide.asp?l1=events&l
2=ipxact-ug1lib&fn=def
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References
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XML tutorial
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XML Schema
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http://www.w3schools.com/xml/xml_elements.a
sp
http://www.w3schools.com/schema/default.asp
IP-XACT-1.4-specification.pdf (from Spirit
Consortium)
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Thanks!
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