KR100452506B1 - Apparatus and method for interface between physical layers in asynchronous transfer mode - Google Patents

Abstract

The present invention is installed between the first physical layer (or PHY layer) and the second physical layer (or another PHY layer) to interface the data and control signals transmitted in the UTOPIA interface standard between them and is provided with a plurality of interface blocks In the interface device, each of the plurality of interface blocks, the first flip-flop for buffering the txclav signal of the first physical layer, the inverter for phase-inverting the signal of the first flip-flop to output the rxenb_n signal, and Performing a logical AND operation on the output signal of the first flip-flop and the rxdata signal of the second physical layer; and performing an AND operation on the output signal of the first flip-flop and the rxsoc signal of the second physical layer. A negative logical product for performing a negative logical product operation on a second logical AND device, an output signal of the first flip-flop, and an rxclav signal of the second physical layer And a second flip-flop for buffering the output signals outputted from the first and second logical AND elements and the txdata signal, txsoc signal, and txenb_n signal separately. It provides a physical inter-layer interface device.

Description

Apparatus and method for interface between physical layers in asynchronous transfer mode}

The present invention relates to an interface between layers in an asynchronous transfer mode (ATM), and more particularly, to an inter-physical layer interface device and a method of an asynchronous transfer mode suitable for performing an interface between physical layers.

In general, ATM is determined by ITU-T (formerly CCITT) as a transmission method of B-ISDN (Broadband ISDN) in 1988, and is a transmission and switching technology that is the core of B-ISDN. This is a method of dividing all information into fixed length blocks called ATM cells and transmitting them sequentially. Such ATM is a dedicated-connection switching technology that divides digital data into 53 bytes of cells or packets and transmits them through a medium using digital signal technology. One cell is individually processed asynchronously with respect to the other cells and placed in a queue for multiplexing for circuit sharing.

The header contains a Virtual Channel Identifier (VCI), a Virtual Path Identifier (VPI) to identify the connection to which the cell belongs, and a Cell Loss Priority (Cell) indicating whether the cell should be discarded during congestion. Fields such as Loss Priority (CLP), Payload Type (PT) for distinguishing network control information, and Header Error Control (HEC) for detecting and controlling header errors. The characteristic of ATM multiplexing is that multiplexing efficiency higher than L division can be achieved by statistical multiplexing, and the transmission band allocated to individual communication can be freely set.

Because ATM is designed to be easier to implement in hardware than software, it is possible to speed up processing. Although the transmission speed of the ATM network being mentioned is about 155.520 Mbps or 622.080 Mbps, the IEEE spectrum reports that the speed is expected to reach 10 Gbps soon. ATM, along with SONET and several other technologies, is the core technology of the broadband ISDN (BISDN).

1 is a block diagram illustrating a conventional ATM layer and a physical layer.

Here, reference numeral 10 is an ATM layer, and 20 is a physical layer.

The UTOPIA (Universal Test and Operations Physical Interface for ATM) is an interface defined between the ATM layer and the PHY layer.

Thus, the ATM layer 10 performs a master function and provides a clock and data to the physical layer 20. In addition, the physical layer 20 performs a slave function and passively receives a clock and data.

The signal configuration in the basic UTOPIA interface is as follows, as shown in FIG.

Signals for data sent from the ATM layer 10 to the physical layer 20 are transmitted by txclk (Transfer Clock), txclav (Transfer Cell Available), txenb (Transfer Enable), txsoc (Transfer Start Of Cell), and txdata (8bit). Signals for data sent from the physical layer 20 to the ATM layer 10 include rxclk (Receiver Clock), rxclav (ReceiverCell Available), rxenb (Receiver Enable), rxsoc (Receiver Start Of Cell), and rxdata (8bit). There is).

FIG. 2 is a UTOPIA timing diagram of each signal in FIG. 1.

So, the process for giving data from the ATM layer 10 to the physical layer 20 is as follows.

The ATM layer 10 provides a txclk signal, which is a clock for all operations, to the physical layer 20, and all handshaking between the two layers proceeds in synchronization with the txclk signal.

Once, txclav, which means that the cell can receive a cell in the physical layer 20, is first displayed as "1", the ATM layer 10 knows that the physical layer 20 can receive a cell. , set the txenb_n signal to "0". At the same time, data is sent to the txdata signal by displaying the txsoc signal, which indicates that the cell is the first byte.

After the transmission of one cell, the txenb_n signal returns to "1".

The physical layer 20 leaves the txclav signal as "1" if it can receive more cells, and changes the value of the txclav signal to "0" if it cannot receive a cell.

The process for giving data from the physical layer 20 to the ATM layer 10 is almost similar, but the giving of the cell becomes the physical layer 20.

Once the rxenb_n signal, which indicates that the ATM layer 10 is in a state capable of receiving a cell, is set to "0", the rxclav signal is set to "1" when the physical layer 20 is able to send a cell. At the same time, the rxsoc signal, which means the first byte of the cell, is displayed as "1", and the rxdata signal is loaded with the cell.

However, in the conventional UTOPIA interface, there is no definition of an interface between physical layers. When performing an interface between physical layers, since both sides have the same signal, even though a separate block is required to act as an interface in the middle, there is a limit in the prior art that there is no technology for implementing such an interface between physical layers.

Accordingly, the present invention has been proposed to solve the conventional problems as described above, and an object of the present invention is to provide an inter-physical layer interface device and a method of an asynchronous transmission method that can perform the interface between physical layers.

Another object of the present invention is to provide an inter-physical layer interface device and a method of an asynchronous transmission method capable of performing an interface between physical layers so as to be suitable for an experiment between an ATM meter providing a physical layer interface and another physical layer.

The present invention for achieving the above object is provided between the first physical layer (or PHY layer) and the second physical layer (or another PHY layer) between the data and control signals transmitted to the UTOPIA interface standard between them In an interface device having an interface and provided with a plurality of interface blocks, each of the plurality of interface blocks includes a first flip-flop for buffering a txclav signal of a first physical layer, and a phase inverted signal of the first flip-flop to rxenb_n. An inverter for outputting a signal, a first AND device for performing an AND operation on the output signal of the first flip-flop, and the rxdata signal of the second physical layer, the output signal of the first flip-flop, and the second physical layer Subtracts a second AND element for performing an AND operation on the rxsoc signal, an output signal of the first flip-flop, and an rxclav signal of the second physical layer. A second logical logic device for performing a positive logic operation, and a second output buffering an output signal output from the first and second logical product and the negative logical device to separately output a txdata signal, a txsoc signal, and a txenb_n signal, respectively. Provided are an inter-physical layer interface device of an asynchronous transmission method including a flip-flop.

In addition, in order to achieve the above object, the interface method according to an embodiment of the present invention between the first and second physical layers for transmitting and receiving a clock and data in an asynchronous transmission method (ATM), In the interface method between the first physical layer (or PHY layer) and the second physical layer (or another PHY layer) for transmitting and receiving clock and data to and from the ATM, the txclav signal input from the first physical layer is " Determining whether the txclav signal is "1" by the first step, changing the rxenb_n signal to "0", outputting the signal to the second physical layer, and then outputting the second physical layer to the second physical layer. Determining whether the rxsoc signal and the rxdata signal inputted from the data are valid data;

When the rxsoc signal and the rxdata signal are determined to be valid data by the second step, an inverting value of the rxclav signal input from the second physical layer is put into the txenb_n signal and output to the first physical layer, and the rxsoc signal and the rxdata signal are output. It provides a method of inter-physical layer interface of the asynchronous transmission method comprising the step of outputting the signal value to the txsoc signal and the txdata signal to the first physical layer, respectively.

1 is a block diagram of a conventional ATM layer and a physical layer of the transmission layer,

FIG. 2 is a UTOPIA timing diagram of each signal in FIG. 1;

3 is a block diagram of a physical layer interface device of the asynchronous transmission method according to the present invention,

4 is a detailed block diagram of an interface unit in FIG. 3;

5 is a flowchart illustrating a method for interface between physical layers in an asynchronous transmission method according to the present invention.

Explanation of symbols on the main parts of the drawings

10: ATM layer 20: physical layer

30 interface unit 31 first flip-flop

32: inverter 33: first logical product

34: second logical AND element 35: negative logical AND element

36: second flip-flop

Hereinafter, an embodiment according to the present invention configured as described above, the physical layer interface device of the asynchronous transmission method and the technical idea of the method will be described in detail with reference to the drawings.

3 is a block diagram of a physical layer interface device of the asynchronous transmission method according to the present invention.

As shown in FIG. 3, the interface device of the present invention includes a first physical layer (or PHY layer) 20a and a second physical layer (or another PHY layer) capable of transmitting / receiving clock and data according to the UTOPIA interface standard. 20b); It is installed between the first physical layer (or PHY layer) 20a and the second physical layer (or another PHY layer) 20b to interface data and control signals transmitted in UTOPIA interface standard between them in both directions. It is configured to include an interface unit 30 having a plurality of interface blocks (30a, 30b) therein.

On the other hand, each of the plurality of interface blocks (30a, 30b) of the interface unit 30, the first flip-flop 31 for buffering the txclav signal of the first physical layer (20a); An inverter (32) for phase inverting the signal of the first flip-flop (31) and outputting an rxenb_n signal; A first logical AND element (33) for performing an AND operation on the output of the first flip-flop (31) and the rxdata signal of the second physical layer (20b); A second logical AND element (34) for performing an AND operation on the output of the first flip-flop (31) and the rxsoc signal of the second physical layer (20b); A negative logical element (35) for performing negative logic multiplication on the output of the first flip-flop (31) and the rxclav signal of the second physical layer (20b); A second flip-flop 36 which receives and buffers the outputs of the first and second logical product elements 33 and 34 and the negative logical element 35 to output a txdata signal, a txsoc signal, and a txenb_n signal It is configured to include.

5 is a flowchart illustrating a method for interface between physical layers in an asynchronous transmission method according to the present invention.

As shown therein, the first step ST11 determines whether the txclav signal input from the first physical layer 20a is "1"; If the txclav signal is "1", changing the rxenb_n signal to "0" and determining whether the rxsoc signal and the rxdata signal are valid data (ST12) (ST13); If the rxsoc signal and the rxdata signal are valid data, the inverting value of the rxclav signal is put into the txenb_n signal and the rxsoc signal and the rxdata signal are put into the txsoc signal and the txdata signal, respectively (ST14) (ST15). To perform, including.

The physical layer interface device of the asynchronous transmission method according to the present invention configured as described above and the operation of the method will be described in detail with reference to the accompanying drawings.

First, the present invention intends to be able to perform an interface between physical layers so as to be suitable for an experiment with an ATM meter that provides a physical layer interface and another physical layer.

In FIG. 3, the first physical layer 20a on the left side is set as a transmit (tx) signal in FIG. 4, and the second physical layer 20b on the right side in FIG. 3 is set as a receive (rx) signal in FIG. 4. Can be.

Thus, the interface unit 30 receives or outputs the transmission signals txclk, txdata, txsoc, txenb_n, txclav and the reception signals rxclk, rxdata, rxsoc, rxclav, rxenb_n.

The first flip-flop 31 buffers the txclav signal of the first physical layer 20a.

The inverter 32 inverts the signal of the first flip-flop 31 and outputs an rxenb_n signal to be input to the second physical layer 20b.

The first AND product 33 performs an AND operation on the output of the first flip-flop 31 and the rxdata signal of the second physical layer 20b.

The second AND device 34 performs an AND operation on the output of the first flip-flop 31 and the rxsoc signal of the second physical layer 20b.

The negative logical element 35 performs a negative logical product operation on the output of the first flip-flop 31 and the rxclav signal of the second physical layer 20b.

The second flip-flop 36 receives and buffers the outputs of the first and second logical product elements 33 and 34 and the negative logical element element 35 to output a txdata signal, a txsoc signal, and a txenb_n signal.

As shown in reference numerals 30a and 30b of FIG. 3, two interface parts that are actually entered between physical layers are operated in reverse directions.

The operation of the present invention will be described with reference to FIG. 5 as follows.

First, data flows from the rx signal to the tx signal. That is, it flows from right to left as seen in FIGS. 3 and 4.

According to the timing diagram of FIG. 2, the data in the received signal is valid when the rxenb_n signal is "0" and the rxclav signal is "1", and the data in the transmit signal is the txclav signal "1" and the txenb_n signal is "0". You can see that it is valid.

In order to match the received signal with the transmitted signal, once the txclav signal becomes "1", the rxenb_n signal is changed to "0". When the rxclav signal is input and valid data is loaded on the rxsoc and rxdata signals, the inverting value of the rxclav signal is put in the txenb_n signal, and the rxsoc and rxdata signal values are put in the txsoc and txdata signals, respectively.

The transmit clocks txclk and receive rxclk pass clocks received from the outside as they are and are used for synchronization clocks with the external physical layer.

Therefore, the signal passing the txclav signal to the first flip-flop 31 is inverted by the inverter 32 and output as the rxenb_n signal.

The rxclav signal is passed through the first flip-flop 31 and the rxdata signal is logically multiplied by the first logical AND element 33 and then passed through the second flip-flop 36 to output the txdata signal.

The txclav signal is passed through the first flip-flop 31 and the rxsoc signal is logically multiplied by the second logical AND element 34, and then passed through the second flip-flop 36 to output the txsoc signal.

After the txclav signal passes through the first flip-flop 31 and the rxclav signal through the negative logic element 35, the second flip-flop 36 passes through the second flip-flop 36 to output the txenb_n signal.

In addition, as shown in FIG. 3, two interface units 30 of FIG. 4 are interposed between the physical layers.

In both cases, data flows from the receiving side to the transmitting side, but the data flows from the right side to the left side and the data flows from the left side to the right side.

As such, the present invention performs the interface between physical layers.

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

As described above, the physical layer interface device and the method of the asynchronous transmission method according to the present invention is useful when trying to experiment with the interface of the other physical layer with the interface of the physical layer, such as ATM meter by enabling the interface between the physical layer. There is an effect that can be applied.

In addition, since UTOPIA is an interface with a signal definition, the present invention also follows the signal definition of UTOPIA, so that the interface between physical layers can be easily implemented without additional logic. There will also be savings.

Claims (5)

The first physical layer (or PHY layer) and the second physical layer (or another PHY layer) capable of transmitting and receiving clocks and data according to the UTOPIA interface specification: Is provided between the first physical layer and the second physical layer to interface between the data and control signals transmitted in the UTOPIA interface standard between them and consists of an interface unit having a plurality of interface blocks therein, In each of the interface blocks of the interface unit, txclav / rxenb_n converting means for phase-inverting the txclav signal input from the first physical layer, converting the signal into rxenb_n signal, and outputting the signal to the second physical layer, and the input from the second physical layer. rxdata / txdata conversion means for performing an AND operation on the rxdata signal to the txclav signal and converting it into a txdata signal, and an rxsoc / txsoc for performing an AND operation on the rxsoc signal input from the second physical layer to perform an OR operation on the txclav signal. And rxclav / txenb_n converting means for converting the rxclav signal inputted from the second physical layer into a txenb_n signal by performing a negative logic multiplication with the txclav signal. 2. The method of claim 1, wherein the txclav / rxenb_n converting means comprises a first flip-flop for buffering the txclav signal input from the first physical layer and an inverter for phase-inverting the output of the first flip-flop. Physical layer interface device of asynchronous transmission method. As an interface method between a first physical layer (or PHY layer) and a second physical layer (or another PHY layer) capable of transmitting and receiving clock and data according to the UTOPIA interface standard, A first step of determining whether a txclav signal input from the first physical layer is "1"; If the txclav signal is "1", a second step of changing the rxenb_n signal to "0" and outputting it to the second physical layer, and then determining whether the rxsoc signal and the rxdata signal input from the second physical layer are valid data. Wow; If the rxsoc signal and the rxdata signal are valid data, an inverting value of the rxclav signal inputted from the second physical layer is put into the txenb_n signal and output to the first physical layer, and the values of the rxsoc signal and the rxdata signal are respectively transmitted to the txsoc signal. And a third step of outputting the signal to the first physical layer in a txdata signal. The method of claim 1, wherein the rxdata / txdata converting means and the rxsoc / txsoc converting means are logical AND elements, the rxclav / txenb_n converting means are negative logical elements, and the buffering means is a second flip-flop. Physical layer interface device of asynchronous transmission method. The apparatus of claim 1, wherein the interface unit provides the first and second physical layers as a transmission clock and a reception clock using a clock signal provided from the outside.