Semiconductor intellectual property core
Encyclopedia
In electronic design a semiconductor
intellectual property core, IP core, or IP block is a reusable unit of logic, cell, or chip layout design that is the intellectual property
of one party. IP cores may be license
d to another party or can be owned and used by a single party alone. The term is derived from the licensing of the patent
and source code copyright
intellectual property rights that subsist in the design. IP cores can be used as building blocks within ASIC
chip designs or FPGA
logic designs.
. By licensing a design multiple times, IP core licensor spread the cost of development among multiple chip makers. IP cores for standard processors, interfaces, and internal functions have enabled chip makers to put more of their resources into developing the differentiating features of their chips. As a result, chip makers have developed new innovations faster.
The licensing and use of IP cores in chip design came into common practice in the 1990s. There were many licensors and also many foundries competing on the market. Today, the most widely licensed IP cores are from MIPS Technologies
and ARM Holdings
.
design what a library
is for computer programming
or a discrete integrated circuit
component is for printed circuit board
design.
. Synthesizable cores are delivered in a hardware description language
such as Verilog
or VHDL
. These are analogous to high level languages
such as C in the field of computer programming. IP cores delivered to chip makers as RTL permit chip designers to modify designs (at the functional level), though many IP vendors offer no warranty or support for modified designs.
IP cores are also sometimes offered as generic gate-level netlist
s. The netlist is a boolean-algebra representation of the IP's logical function implemented as generic gate
s or process specific standard cell
s. An IP core implemented as generic gates is portable to any process technology. A gate-level netlist is analogous to an assembly-code listing in the field of computer programming. A netlist gives the IP core vendor reasonable protection against reverse engineering.
Both netlist and synthesizable cores are called "soft cores", as both allow a synthesis, placement and route (SPR) design flow.
Analog
and mixed-signal
logic are generally defined as a lower-level, physical description. Hence, analog IP (SerDes
, PLLs, DAC
, ADC
, etc.) are provided to chip makers in transistor-layout format (such as GDSII
.) Digital IP cores are sometimes offered in layout format, as well.
Such cores, whether analog or digital, are called "hard cores" (or hard macros), because the core's application function cannot be meaningfully modified by chip designers. Transistor layouts must obey the target foundry's process design rules, and hence, hard cores delivered for one foundry's process cannot be easily ported to a different process or foundry. Merchant foundry operators (such as IBM
, Fujitsu
, Samsung
, TI
, etc.) offer a variety of hard-macro IP functions built for their own foundry process, helping to ensure customer lock-in.
designs. Their instruction set
s vary from small 8-bit processors, such as the 8051
and PIC
to 32-bit processors such as the ARM architecture
s or MIPS architecture
s. Such processors form the "brains" of many embedded system
s.
IP cores are also licensed for a variety of peripheral controllers such as for SDRAM
, ethernet
, LCD display
, AC'97 audio, and USB. Many of those interfaces require digital logic as well as analog IP cores in order to drive and receive high speed, high voltage, or high impedance
signals outside of the chip.
"Hardwired" (as opposed to software programmable soft microprocessors described above) digital logic IP cores are also licensed for fixed functions such as MP3
audio decode, 3D GPU, digital video
decode, and other DSP
functions such as FFT, DCT
, or Viterbi
coding.
and theft of intellectual property.
An incomplete list of IP core licensors has been compiled.
cores. OpenCores.org
offers a wide variety of designs, mostly written in VHDL and Verilog
. Most of these cores are provided under the GPL or BSD-like licenses (see OpenCores licenses for details).
Semiconductor
A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...
intellectual property core, IP core, or IP block is a reusable unit of logic, cell, or chip layout design that is the intellectual property
Intellectual property
Intellectual property is a term referring to a number of distinct types of creations of the mind for which a set of exclusive rights are recognized—and the corresponding fields of law...
of one party. IP cores may be license
License
The verb license or grant licence means to give permission. The noun license or licence refers to that permission as well as to the document recording that permission.A license may be granted by a party to another party as an element of an agreement...
d to another party or can be owned and used by a single party alone. The term is derived from the licensing of the patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
and source code copyright
Copyright
Copyright is a legal concept, enacted by most governments, giving the creator of an original work exclusive rights to it, usually for a limited time...
intellectual property rights that subsist in the design. IP cores can be used as building blocks within ASIC
Application-specific integrated circuit
An application-specific integrated circuit is an integrated circuit customized for a particular use, rather than intended for general-purpose use. For example, a chip designed solely to run a cell phone is an ASIC...
chip designs or FPGA
Field-programmable gate array
A field-programmable gate array is an integrated circuit designed to be configured by the customer or designer after manufacturing—hence "field-programmable"...
logic designs.
History
IP cores in the electronic design industry have had a profound impact on the design of systems on a chipSystem-on-a-chip
A system on a chip or system on chip is an integrated circuit that integrates all components of a computer or other electronic system into a single chip. It may contain digital, analog, mixed-signal, and often radio-frequency functions—all on a single chip substrate...
. By licensing a design multiple times, IP core licensor spread the cost of development among multiple chip makers. IP cores for standard processors, interfaces, and internal functions have enabled chip makers to put more of their resources into developing the differentiating features of their chips. As a result, chip makers have developed new innovations faster.
The licensing and use of IP cores in chip design came into common practice in the 1990s. There were many licensors and also many foundries competing on the market. Today, the most widely licensed IP cores are from MIPS Technologies
MIPS Technologies
MIPS Technologies, Inc. , formerly MIPS Computer Systems, Inc., is most widely known for developing the MIPS architecture and a series of pioneering RISC chips. MIPS provides processor architectures and cores for digital home, networking and mobile applications.MIPS Computer Systems Inc. was...
and ARM Holdings
ARM Holdings
ARM Holdings plc is a British multinational semiconductor and software company headquartered in Cambridge. Its largest business is in processors, although it also designs, licenses and sells software development tools under the RealView and KEIL brands, systems and platforms, system-on-a-chip...
.
Types of IP cores
The IP core can be described as being for chipMicroprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
design what a library
Library (computer science)
In computer science, a library is a collection of resources used to develop software. These may include pre-written code and subroutines, classes, values or type specifications....
is for computer programming
Computer programming
Computer programming is the process of designing, writing, testing, debugging, and maintaining the source code of computer programs. This source code is written in one or more programming languages. The purpose of programming is to create a program that performs specific operations or exhibits a...
or a discrete integrated circuit
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
component is for printed circuit board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
design.
Soft cores
IP cores are typically offered as synthesizable RTLRegister Transfer Language
In computer science, register transfer language is a term used to describe a kind of intermediate representation that is very close to assembly language, such as that which is used in a compiler. Academic papers and textbooks also often use a form of RTL as an architecture-neutral assembly language...
. Synthesizable cores are delivered in a hardware description language
Hardware description language
In electronics, a hardware description language or HDL is any language from a class of computer languages, specification languages, or modeling languages for formal description and design of electronic circuits, and most-commonly, digital logic...
such as Verilog
Verilog
In the semiconductor and electronic design industry, Verilog is a hardware description language used to model electronic systems. Verilog HDL, not to be confused with VHDL , is most commonly used in the design, verification, and implementation of digital logic chips at the register-transfer level...
or VHDL
VHSIC Hardware Description Language
VHDL is a hardware description language used in electronic design automation to describe digital and mixed-signal systems such as field-programmable gate arrays and integrated circuits.- History :...
. These are analogous to high level languages
High-level programming language
A high-level programming language is a programming language with strong abstraction from the details of the computer. In comparison to low-level programming languages, it may use natural language elements, be easier to use, or be from the specification of the program, making the process of...
such as C in the field of computer programming. IP cores delivered to chip makers as RTL permit chip designers to modify designs (at the functional level), though many IP vendors offer no warranty or support for modified designs.
IP cores are also sometimes offered as generic gate-level netlist
Netlist
The word netlist can be used in several different contexts, but perhaps the most popular is in the field of electronic design. In this context, a "netlist" describes the connectivity of an electronic design....
s. The netlist is a boolean-algebra representation of the IP's logical function implemented as generic gate
Logic gate
A logic gate is an idealized or physical device implementing a Boolean function, that is, it performs a logical operation on one or more logic inputs and produces a single logic output. Depending on the context, the term may refer to an ideal logic gate, one that has for instance zero rise time and...
s or process specific standard cell
Standard cell
In semiconductor design, standard cell methodology is a method of designing application-specific integrated circuits with mostly digital-logic features. Standard cell methodology is an example of design abstraction, whereby a low-level very-large-scale integration layout is encapsulated into an...
s. An IP core implemented as generic gates is portable to any process technology. A gate-level netlist is analogous to an assembly-code listing in the field of computer programming. A netlist gives the IP core vendor reasonable protection against reverse engineering.
Both netlist and synthesizable cores are called "soft cores", as both allow a synthesis, placement and route (SPR) design flow.
Hard cores
Hard cores, by the nature of their low-level representation, offer better predictability of chip performance in terms of timing performance and area.Analog
Analogue electronics
Analogue electronics are electronic systems with a continuously variable signal, in contrast to digital electronics where signals usually take only two different levels. The term "analogue" describes the proportional relationship between a signal and a voltage or current that represents the signal...
and mixed-signal
Mixed-signal integrated circuit
A mixed-signal integrated circuit is any integrated circuit that has both analog circuits and digital circuits on a single semiconductor die.- Examples :...
logic are generally defined as a lower-level, physical description. Hence, analog IP (SerDes
SerDes
A Serializer/Deserializer is a pair of functional blocks commonly used in high speed communications to compensate for limited input/output. These blocks convert data between serial data and parallel interfaces in each direction...
, PLLs, DAC
Digital-to-analog converter
In electronics, a digital-to-analog converter is a device that converts a digital code to an analog signal . An analog-to-digital converter performs the reverse operation...
, ADC
Analog-to-digital converter
An analog-to-digital converter is a device that converts a continuous quantity to a discrete time digital representation. An ADC may also provide an isolated measurement...
, etc.) are provided to chip makers in transistor-layout format (such as GDSII
GDSII
GDSII stream format, common acronym GDSII, is a database file format which is the de facto industry standard for data exchange of integrated circuit or IC layout artwork. It is a binary file format representing planar geometric shapes, text labels, and other information about the layout in...
.) Digital IP cores are sometimes offered in layout format, as well.
Such cores, whether analog or digital, are called "hard cores" (or hard macros), because the core's application function cannot be meaningfully modified by chip designers. Transistor layouts must obey the target foundry's process design rules, and hence, hard cores delivered for one foundry's process cannot be easily ported to a different process or foundry. Merchant foundry operators (such as IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
, Fujitsu
Fujitsu
is a Japanese multinational information technology equipment and services company headquartered in Tokyo, Japan. It is the world's third-largest IT services provider measured by revenues....
, Samsung
Samsung
The Samsung Group is a South Korean multinational conglomerate corporation headquartered in Samsung Town, Seoul, South Korea...
, TI
Texas Instruments
Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
, etc.) offer a variety of hard-macro IP functions built for their own foundry process, helping to ensure customer lock-in.
Licensed functionality
Many of the best known IP cores are soft microprocessorSoft microprocessor
A soft microprocessor is a microprocessor core that can be wholly implemented using logic synthesis...
designs. Their instruction set
Instruction set
An instruction set, or instruction set architecture , is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O...
s vary from small 8-bit processors, such as the 8051
Intel 8051
The Intel MCS-51 is a Harvard architecture, single chip microcontroller series which was developed by Intel in 1980 for use in embedded systems. Intel's original versions were popular in the 1980s and early 1990s. While Intel no longer manufactures the MCS-51, binary compatible derivatives remain...
and PIC
PIC microcontroller
PIC is a family of Harvard architecture microcontrollers made by Microchip Technology, derived from the PIC1650 originally developed by General Instrument's Microelectronics Division...
to 32-bit processors such as the ARM architecture
ARM architecture
ARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...
s or MIPS architecture
MIPS architecture
MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
s. Such processors form the "brains" of many embedded system
Embedded system
An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...
s.
IP cores are also licensed for a variety of peripheral controllers such as for SDRAM
SDRAM
Synchronous dynamic random access memory is dynamic random access memory that is synchronized with the system bus. Classic DRAM has an asynchronous interface, which means that it responds as quickly as possible to changes in control inputs...
, ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
, LCD display
Liquid crystal display
A liquid crystal display is a flat panel display, electronic visual display, or video display that uses the light modulating properties of liquid crystals . LCs do not emit light directly....
, AC'97 audio, and USB. Many of those interfaces require digital logic as well as analog IP cores in order to drive and receive high speed, high voltage, or high impedance
Electrical impedance
Electrical impedance, or simply impedance, is the measure of the opposition that an electrical circuit presents to the passage of a current when a voltage is applied. In quantitative terms, it is the complex ratio of the voltage to the current in an alternating current circuit...
signals outside of the chip.
"Hardwired" (as opposed to software programmable soft microprocessors described above) digital logic IP cores are also licensed for fixed functions such as MP3
MP3
MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is a patented digital audio encoding format using a form of lossy data compression...
audio decode, 3D GPU, digital video
Digital video
Digital video is a type of digital recording system that works by using a digital rather than an analog video signal.The terms camera, video camera, and camcorder are used interchangeably in this article.- History :...
decode, and other DSP
Digital signal processing
Digital signal processing is concerned with the representation of discrete time signals by a sequence of numbers or symbols and the processing of these signals. Digital signal processing and analog signal processing are subfields of signal processing...
functions such as FFT, DCT
Discrete cosine transform
A discrete cosine transform expresses a sequence of finitely many data points in terms of a sum of cosine functions oscillating at different frequencies. DCTs are important to numerous applications in science and engineering, from lossy compression of audio and images A discrete cosine transform...
, or Viterbi
Viterbi decoder
A Viterbi decoder uses the Viterbi algorithm for decoding a bitstream that has beenencoded using forward error correction based on a convolutional code....
coding.
Vendors
IP core developers and licensors range in size from individuals to multi-billion dollar corporations. Developers, as well as their chip making customers are located throughout the world. IP development and licensing is less common in nations with lax enforcement of laws against the infringementInfringement
Infringement, when used alone, has several possible meanings in the English language.In a legal context, an infringement refers to the violation of a law or a right. This includes intellectual property infringements such as:*Copyright infringement...
and theft of intellectual property.
An incomplete list of IP core licensors has been compiled.
Open source
There are also providers of open sourceOpen source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
cores. OpenCores.org
OpenCores
OpenCores is the world's largest open source hardware community developing digital open source hardware through electronic design automation, with a similar ethos to the free software movement. OpenCores hopes to eliminate redundant design work and slash development costs. A number of companies...
offers a wide variety of designs, mostly written in VHDL and Verilog
Verilog
In the semiconductor and electronic design industry, Verilog is a hardware description language used to model electronic systems. Verilog HDL, not to be confused with VHDL , is most commonly used in the design, verification, and implementation of digital logic chips at the register-transfer level...
. Most of these cores are provided under the GPL or BSD-like licenses (see OpenCores licenses for details).
Aggregators
Intellectual property aggregators keep catalogs of cores from multiple vendors and provide search and marketing services to their customers.External links
- Open cores "design and publish core" (under LGPL Licence)
- Altera cores Free reference IP cores for FPGAs