Communications Communication (from la, communicare, meaning "to share" or "to be in relation with") is usually defined as the transmission of information. The term may also refer to the message communicated through such transmissions or the field of inqui ...

and networking riser (CNR) is a

slot Slot, the slot or Slots may refer to: People * Arne Slot (born 1978), Dutch footballer * Gerrie Slot (born 1954), Dutch cyclist * Hanke Bruins Slot (born 1977), Dutch politician * Tonny Bruins Slot (born 1947), Dutch association football coac ...

found on certain PC

motherboards A motherboard (also called mainboard, main circuit board, mb, mboard, backplane board, base board, system board, logic board (only in Apple computers) or mobo) is the main printed circuit board (PCB) in general-purpose computers and other expand ...

and used for specialized networking, audio, and telephony equipment. A motherboard manufacturer can choose to provide

audio Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to: Sound *Audio signal, an electrical representation of sound *Audio frequency, a frequency in the audio spectrum * Digital audio, representation of soun ...

, networking, or

modem A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by modulating one or more c ...

functionality in any combination on a CNR card. CNR slots were once commonly found on

Pentium III The Pentium III (marketed as Intel Pentium III Processor, informally PIII or P3) brand refers to Intel's 32-bit x86 desktop and mobile CPUs based on the sixth-generation P6 microarchitecture introduced on February 28, 1999. The brand's initial ...

-class motherboards, but have since been phased out in favor of on-board or embedded components.

Technology

Physically, a CNR slot has two rows of 30 pins, with two possible pin configurations: Type A and Type B, each with different pin assignments. CNR Type A uses 8-pin PHY interface, while Type B uses 17-pin

media-independent interface The media-independent interface (MII) was originally defined as a standard interface to connect a Fast Ethernet (i.e., ) media access control (MAC) block to a PHY chip. The MII is standardized by IEEE 802.3u and connects different types of PHY ...

(''MII'') bus LAN interface. Both types carry

USB Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply ( interfacing) between computers, peripherals and other computers. A broa ...

and

AC'97 AC'97 (''Audio Codec '97;'' also MC'97 for ''Modem Codec '97'') is an audio codec standard developed by Intel Architecture Labs in 1997. The standard was used in motherboards, modems, and sound cards. The specification covers two types of comp ...

signals. As with AMR, CNR had the cost savings potential for manufacturers by removing analog I/O components from the motherboard. This allowed the manufacturer to only certify with the US

Federal Communications Commission The Federal Communications Commission (FCC) is an independent agency of the United States federal government that regulates communications by radio, television, wire, satellite, and cable across the United States. The FCC maintains jurisd ...

(FCC) for the CNR card, and not the entire motherboard. This resulted in a quicker production-to-market time for new motherboards, and allowed mass-production of CNR cards to be used on multiple motherboards. The ACR slot was a competing specification developed by a group of third-party vendors. Its principal advantage over CNR was the

backwards-compatible Backward compatibility (sometimes known as backwards compatibility) is a property of an operating system, product, or technology that allows for interoperability with an older legacy system, or with input designed for such a system, especially ...

slot layout which allowed it to use both AMR and ACR cards. The same group also developed a physically smaller version, the MDC.

History

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the devel ...

developed the CNR slot to replace its own audio/modem riser (AMR) technology, drawing on two distinct advantages over the AMR slot it replaced; CNR was both capable of being either software based (CPU-controlled) or hardware accelerated (dedicated

ASIC An application-specific integrated circuit (ASIC ) is an integrated circuit (IC) chip customized for a particular use, rather than intended for general-purpose use, such as a chip designed to run in a digital voice recorder or a high-effici ...

), and was

plug-and-play In computing, a plug and play (PnP) device or computer bus is one with a specification that facilitates the recognition of a hardware component in a system without the need for physical device configuration or user intervention in resolving resou ...

compatible. On some motherboards, a CNR slot replaced the last

PCI PCI may refer to: Business and economics * Payment card industry, businesses associated with debit, credit, and other payment cards ** Payment Card Industry Data Security Standard, a set of security requirements for credit card processors * Prov ...

slot, but most motherboard manufacturers engineered boards which allow the CNR and last PCI slot to share the same space. With the integration of components such as ethernet and audio into the motherboard, the CNR is obsolete, and is not found on PC motherboards anymore.

External links

CNR Specification 1.1

pinouts.ru - CNR slot pinout and signals
Motherboard expansion slot {{compu-hardware-stub

Technology

History

See also

External links