VLYNQ
Encyclopedia
VLYNQ is a proprietary interface
developed by Texas Instruments
and used for broadband
products, such as WLAN
and modems, VOIP processors
and audio and digital media processor
chips. The chip implements a full-duplex serial communications
interface
that enables the extension of an internal bus segment to one or more external physical devices. The external devices are mapped into local, physical address space and appear as if they are on the internal bus. Multiple VLYNQ devices are daisy-chained
, communication is peer-to-peer, host/peripheral. Data transferred over the VLYNQ interface is 8B/10B encoded
and packetized.
VLYNQ is the name of a proprietary interface developed by Texas Instruments. It's used for TI's broadband products, such as modems and WLAN, voice broadband processors, digital media processors, and OMAP media processor chips.
The ACX111 WLAN cards used in AR7 devices look like mini-PCI, but actually they are dual mode cards, that talk both, mini-PCI and VLYNQ.
More information : Design_Connector_VLYNQ_bus.html
When clocked at 125 MHz, a single T/R pair then delivers an effective data throughput of about 73 Mbit/s (for single, 32-bit word transfers), while a dual T/R pair implementation delivers 146 Mbit/s, and a maximum eight-channel version delivers 584 Mbit/s. In-band flow-control lets the interface independently throttle the transmit and receive data streams.
If data packets contain four or 16 words, some of the overhead is eliminated. So on a single channel, data bursts of four words per packet can deliver an effective throughput of 133 Mbit/s. With 16 words per packet, the throughput goes up to 178 Mbit/s. With the maximum eight channels, an effective throughput of over 1400 Mbit/s can be achieved with 16 words per packet. Both the direction and clock source may be software configurable [may be device dependent]. Software may also be used to set the internal clock speed [may be device dependent]. Unused clock lines are held high via an internal pull-up. Unused RX or TX lines may require an external 47k pull-down resistor [may be device dependent]. Software selectable internal pull-downs for signals may be provided on some devices.
SOP, 10 bits
CMD1, 10 bits; or PktType, 10 bits
CMD2, 10 bits; or AdMask, 10 bits
ByteCnt, 10 bits
Address, 10 bits [could be up to 4 words]
Data, 10 bits [could be 'N' words long]
EOP, 10 bits
The IBM patented encoding method used for encoding 8-bit data bytes to 10-bit Transmission Characters. Data bytes are converted to Transmission Characters to improve the physical signal such that the following benefits are achieved: bit synchronization is more easily achieved, design of receivers and transmitters is simplified, error detection is improved, and control characters (i.e., the Special Character) can be distinguished from data characters.
Computer bus
In computer architecture, a bus is a subsystem that transfers data between components inside a computer, or between computers.Early computer buses were literally parallel electrical wires with multiple connections, but the term is now used for any physical arrangement that provides the same...
developed by Texas Instruments
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...
and used for broadband
Broadband
The term broadband refers to a telecommunications signal or device of greater bandwidth, in some sense, than another standard or usual signal or device . Different criteria for "broad" have been applied in different contexts and at different times...
products, such as WLAN
Wireless LAN
A wireless local area network links two or more devices using some wireless distribution method , and usually providing a connection through an access point to the wider internet. This gives users the mobility to move around within a local coverage area and still be connected to the network...
and modems, VOIP processors
Voice over IP
Voice over Internet Protocol is a family of technologies, methodologies, communication protocols, and transmission techniques for the delivery of voice communications and multimedia sessions over Internet Protocol networks, such as the Internet...
and audio and digital media processor
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...
chips. The chip implements a full-duplex serial communications
Serial communications
In telecommunication and computer science, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels...
interface
Interface (computer science)
In the field of computer science, an interface is a tool and concept that refers to a point of interaction between components, and is applicable at the level of both hardware and software...
that enables the extension of an internal bus segment to one or more external physical devices. The external devices are mapped into local, physical address space and appear as if they are on the internal bus. Multiple VLYNQ devices are daisy-chained
Daisy chain (electrical engineering)
In electrical and electronic engineering a daisy chain is a wiring scheme in which multiple devices are wired together in sequence or in a ring...
, communication is peer-to-peer, host/peripheral. Data transferred over the VLYNQ interface is 8B/10B encoded
8B/10B encoding
In telecommunications, 8b/10b is a line code that maps 8-bit symbols to 10-bit symbols to achieve DC-balance and bounded disparity, and yet provide enough state changes to allow reasonable clock recovery. This means that the difference between the count of 1s and 0s in a string of at least 20 bits...
and packetized.
VLYNQ is the name of a proprietary interface developed by Texas Instruments. It's used for TI's broadband products, such as modems and WLAN, voice broadband processors, digital media processors, and OMAP media processor chips.
The ACX111 WLAN cards used in AR7 devices look like mini-PCI, but actually they are dual mode cards, that talk both, mini-PCI and VLYNQ.
More information : Design_Connector_VLYNQ_bus.html
Details
The VLYNQ bus signals include 1 clock signal [CLK], and 1 to 8 Transmit lines [TX0 and TX1 …], and 1 to 8 Receive lines [RX0 and RX1…..]. All VLYNQ signals are dedicated and driven by only one device. The transmit pins of one device connect to the receive lines of the next device. The VLYNQ bus will operate at a maximum clock speed of 125 MHz. However the actual clock speed is dependent on the physical device with the VLYNQ. So a device may have a clock speed other than 125 MHz. For example a device may have an internal 100 MHz [maximum] clock rate, or external 80 MHz [maximum] clock rate.When clocked at 125 MHz, a single T/R pair then delivers an effective data throughput of about 73 Mbit/s (for single, 32-bit word transfers), while a dual T/R pair implementation delivers 146 Mbit/s, and a maximum eight-channel version delivers 584 Mbit/s. In-band flow-control lets the interface independently throttle the transmit and receive data streams.
If data packets contain four or 16 words, some of the overhead is eliminated. So on a single channel, data bursts of four words per packet can deliver an effective throughput of 133 Mbit/s. With 16 words per packet, the throughput goes up to 178 Mbit/s. With the maximum eight channels, an effective throughput of over 1400 Mbit/s can be achieved with 16 words per packet. Both the direction and clock source may be software configurable [may be device dependent]. Software may also be used to set the internal clock speed [may be device dependent]. Unused clock lines are held high via an internal pull-up. Unused RX or TX lines may require an external 47k pull-down resistor [may be device dependent]. Software selectable internal pull-downs for signals may be provided on some devices.
Packet format
The packet format is:SOP, 10 bits
CMD1, 10 bits; or PktType, 10 bits
CMD2, 10 bits; or AdMask, 10 bits
ByteCnt, 10 bits
Address, 10 bits [could be up to 4 words]
Data, 10 bits [could be 'N' words long]
EOP, 10 bits
8B/10B Encoding
- main article: 8B/10B encoding8B/10B encodingIn telecommunications, 8b/10b is a line code that maps 8-bit symbols to 10-bit symbols to achieve DC-balance and bounded disparity, and yet provide enough state changes to allow reasonable clock recovery. This means that the difference between the count of 1s and 0s in a string of at least 20 bits...
The IBM patented encoding method used for encoding 8-bit data bytes to 10-bit Transmission Characters. Data bytes are converted to Transmission Characters to improve the physical signal such that the following benefits are achieved: bit synchronization is more easily achieved, design of receivers and transmitters is simplified, error detection is improved, and control characters (i.e., the Special Character) can be distinguished from data characters.