JP2923891B2 - Continuous cell reception information transfer method and continuous cell reception information transfer system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a UTOPIA interface which is an interface between an ATM layer and a physical layer in ATM communication, and stores information indicating whether received cells are continuously generated in the physical layer in an AT.
The present invention relates to a continuous cell reception information transfer method and a continuous cell reception information transfer system capable of notifying an M layer.

[0002]

2. Description of the Related Art A UTOPIA interface is provided between an ATM layer and a physical layer (PHY layer) in an ATM communication device in order to absorb the diversity of the PHY layer. At present, UTOPIA interface level 1, Version 2.01 is defined in the ATM Forum.

FIG. 3 is a timing chart showing the timing on the receiving (Rx) side of the UTOPIA interface.
In the figure, the Rx Clk signal in (a) shows a transmission clock signal from the ATM layer device, and the Rx Clk signal in (b)
The SOC signal is high active and indicates that Rx Data (received data) is the first byte of valid ATM cell data. Also, Rx Empty * in (c)
The signal is low active and Rx from the PHY layer
Data is invalid, that is, there is no received data in the FIFO of the PHY layer device.
The x Enb * signal is low active, indicating that the ATM layer is ready to receive. And R in (e)
xData indicates 8-bit reception data from the PHY layer device to the ATM layer device. in this way,
By defining the Rx side of the UTOPIA interface, the ATM layer can receive data regardless of which transmission medium is used for the PHY layer.

[0004]

By the way, this UTO
On the Rx side of the PIA interface, continuous cell reception information indicating whether or not the reception cells are continuously generated in the PHY layer is not defined. Sometimes good. For example, when another cell is added between cells received from the PHY layer on the ATM layer device side, a cell buffer for one cell must be provided if there is no continuous cell reception information. If there is continuous cell reception information, AT
At the M layer device side, at the start of ATM cell reception (RxS
(When OC is high) it can determine whether the PHY layer device is receiving the next cell from the ATM network. As a result, it can be immediately determined whether or not a cell can be added, and it is not necessary to provide a cell buffer or the like.

However, as described above, since continuous cell reception information is not defined on the Rx side of the UTOPIA interface, when saving cell buffers and the like,
There is a problem that a signal line for notifying the ATM layer device of continuous cell reception information must be provided separately from the signal line of the UTOPIA interface.

The present invention has been made to solve such a problem, and it is possible to determine whether or not received cells are continuously generated without providing a signal line for notifying continuous cell received information. It is an object of the present invention to provide a continuous cell reception information transfer method and a continuous cell reception information transfer system that can transfer the indicated information from the PHY layer to the ATM layer.

[0007]

According to the present invention, there is provided a continuous cell reception information transfer method for transmitting information from a PHY layer to an ATM layer in an ATM communication apparatus, the information indicating whether or not reception cells are continuously generated in the PHY layer. And when the signal (RxSOC signal) indicating the first byte of valid ATM cell data in the UTOPIA interface indicates a significant level, the received data from the physical layer Is invalid (Rx Empty * signal) and information (Rx Ccel *) indicating whether or not the reception cells are continuously generated.
Information), and when the Rx SOC signal does not indicate a significant level, RxEmp
This is a method of transferring the ty * signal as it is to the ATM layer.

Further, the continuous cell reception information transfer system according to the present invention transfers information indicating whether or not reception cells are continuously generated in the PHY layer from the PHY layer device to the ATM layer device in the ATM communication apparatus. The PHY layer device includes a selection unit that selects and outputs any one of an Rx Empty * signal and Rx Ccel * information,
The TM layer device outputs an Rx Empty * signal and an Rx Ccel * from the output of the selection means of the PHY layer device.
It has a configuration including a reproducing means for reproducing information. P
The selecting means of the HY layer device is configured to select the Rx Ccel * information when the Rx SOC signal indicates a significant level, and select the Rx Empty * signal when the Rx SOC signal does not indicate a significant level. Is done. The reproduction means of the ATM layer device is Rx
When the SOC signal indicates a significant level, PHY
From the signal from the selection means in the layer device, Rx
First reproducing means for reproducing Ccel * information, and Rx SO
A second method for reproducing the Rx Empty * signal from the signal from the selection means when the C signal does not indicate a significant level
And reproduction means. The first reproducing means is a flip-flop which takes in a signal from the selecting means of the PHY layer device by a transmission clock signal, and the second reproducing means inputs a high level to a first input terminal and outputs a high level signal to the PHY layer device. The selector may be a selector that inputs a signal from the selecting means of the device to the second input terminal and selects a signal at the second input terminal when the Rx SOC signal does not indicate a significant level.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. Referring to FIG. 3, when the Rx SOC signal is at a high level, the first byte of valid ATM cell data always appears in Rx Data, so that the Rx Empty * signal is always at a high level. . Therefore, in the PHY layer device, RxS
If the Rx Empty * signal is output as a signal indicating continuous cell reception information when the OC signal is at a high level,
In the M layer, it can be determined whether or not the reception cells continuously occur based on the Rx Empty * signal at this time.

The present invention is based on such a concept. FIG. 1 is a timing chart showing the timing on the Rx side of the UTOPIA interface according to the present invention. In the figure, the Rx Clk signal in (a) shows a transmission clock signal from the ATM layer device, and the Rx SOC signal in (b) is high active and Rx Data
(Received data) is the first byte of valid ATM cell data. Also, Rx Ccel of (c)
* Information is stored in UTOPI in the PHY layer device.
It indicates whether or not a valid cell other than the received cell output on the A interface has been received from the ATM network, that is, whether or not there is continuous cell reception. In FIG. 1, RxCcel * information is low active,
Low level indicates continuous cell reception,
A high level indicates that there is no continuous cell reception.

The original Rx Empty * signal in (d) is a conventional Rx Empty * signal, and a low level indicates that Rx Data from the PHY layer is invalid. In this embodiment, the original Rx Empty * signal does not appear on the UTOPIA interface. (E)
Rx Empty * signal in the present invention is UTOPI
The Rx Empty * signal that appears on the A interface. The Rx Empty * signal indicates continuous cell reception information when the Rx SOC signal is at a high level. The Rx Enb * signal in (f) is low active and indicates that the ATM layer is in a receivable state, and the Rx Dab in (g)
“ta” indicates 8-bit received data from the PHY layer device to the ATM layer device.

Next, the operation will be described with reference to the circuit example of FIG. As shown in FIG. 2, the PHY layer device 300 is provided with a selector 40 for switching and outputting the Rx Ccel * information of (c) and the original (conventional) Rx Empty * signal of (d). The selector 40 is (b)
When the Rx SOC signal is high, the Rx
When the Ccel * information is selected and the Rx SOC signal is at a low level, the original Rx Empty * signal of (d) is selected. The selected output of the selector 40 is Rx of (e) of the present invention.
UTOPIA interface 2 as Empty * signal
00 is sent out. Accordingly, the Rx E of the present invention shown in (e) is used.
Only when the Rx SOC signal is at a high level, the mpty * signal contains the (x) RxCcel * information and in other periods, the (d) contains the conventional Rx Empty * signal.

In the period p in which the first Rx SOC signal shown in FIG. 1 is at the high level, the Rx Ccel * information of (c) indicates the high level, and thus the Rx E of the present invention of (e) is shown.
The mpty * signal also becomes high level during that period (see FIG. 1E). However, the second Rx SOC
In a period q in which the signal is at a high level, RxCcel in (c)
Since the * information indicates a low level, the Rx Empty * signal of the present invention (e) also indicates a low level during that period (see FIG. 1 (e)).

As shown in FIG. 2, the ATM layer device 100 has a flip-flop 20 for reproducing RxCcel * information of (c), that is, information indicating whether or not there is continuous cell reception, and an ATM layer device of (d). A selector 30 for reproducing the original Rx Empty * signal is provided.

The flip-flop 20 is provided with the Rx S of FIG.
The OC signal is input to an enable terminal (high active). Therefore, it operates only when the Rx SOC signal is at a high level. When the Rx SOC signal is at a high level, the flip-flop 20 latches the Rx Empty * signal of the present invention (e) on the UTOPIA interface 200 with the Rx Clk signal of (a). Rx SOC
When the signal is at the high level, the RxE of the present invention shown in FIG.
The mpty * signal is a signal indicating Rx Ccel * information. Therefore, the output of flip-flop 20 is R
x Ccel * information. That is, the flip-flop 20 reproduces the RxCcel * information (c), that is, the information indicating whether or not there is continuous cell reception.

A high level is input to one input terminal (A input terminal) of the selector 30. The other input terminal (B input terminal) has a UTOPIA interface 2
The Rx Empty * signal of the present invention in (e) of FIG. The selector 30 selects and outputs the signal of the A input terminal when the (b) Rx SOC signal input to the selection input terminal is at a high level, and outputs the signal of the B input terminal when the Rx SOC signal is at a low level. Is selected and output. Therefore, when the Rx SOC signal is at a high level,
A high level appears at the output of the selector 30 and when the Rx SOC signal is at a low level, the Rx Em of the present invention shown in FIG.
The pty * signal appears. As described above, the Rx Empty * signal of the present invention when the Rx SOC signal is at the low level indicates the original Rx Empty * signal of (d). When the Rx SOC signal is at a high level,
The original Rx Empty * signal was always at a high level. Therefore, the output of the selector 30 includes the original R of (d).
The x Empty * signal is reproduced and output.

As described above, in the present invention, by utilizing the redundancy in the UTOPIA interface that the Rx Empty * signal always goes high when the Rx SOC signal is high, the Rx Cell using the Rx Empty * signal is used. * Information, ie, information indicating whether there is continuous cell reception, can be transmitted from the PHY layer device to the ATM layer device. Therefore, UTOPIA
Without adding a signal line other than a signal line in the interface, a simple circuit configuration enables the PHY layer device to start the next ATM cell reception from the ATM network (when the Rx SOC signal is at a high level) at the ATM layer device side. It becomes possible to determine whether or not a cell has been received. As a result, it is possible to construct an environment in which a cell buffer and the like need not be provided without adding a signal line.

[0018]

According to the present invention, the continuous cell reception information transfer method uses the Rx Empty * signal as a signal for transferring the Rx Ccel * information when the Rx SOC signal indicates a significant level. When the Rx SOC signal does not indicate a significant level, the Rx Empty * signal is transferred to the ATM layer as it is, so that the PHY layer device does not add any signal lines other than the signal line in the UTOPIA interface. There is an effect that the device can be notified of the continuous cell reception information.

Further, according to the present invention, a continuous cell reception information transfer system is provided, wherein the PHY layer device comprises an Rx Empt.
The ATM layer device includes a selection unit for selecting and outputting any of the y * signal and the RxCcel * information.
Since it is configured to include a reproducing unit for reproducing the pty * signal and the RxCcel * information, the U.S.C.
ATM signal can be sent from PHY layer device without adding signal lines other than signal lines in TOPIA interface.
There is an effect that the continuous cell reception information can be notified to the layer device.

[Brief description of the drawings]

FIG. 1 is a timing chart showing the timing on the Rx side of a UTOPIA interface according to the present invention.

FIG. 2 is a configuration diagram showing a circuit configuration for notifying continuous cell reception information in the continuous cell reception information transfer system according to the present invention.

FIG. 3 is a timing chart showing the timing on the Rx side of the conventional UTOPIA interface.

[Explanation of symbols]

 Reference Signs List 20 flip-flop 30 selector 40 selector 100 ATM layer device 200 UTOPIA interface 300 physical layer device

Claims (5)

(57) [Claims] 1. A continuous cell reception information transfer method for transferring information indicating whether or not received cells are continuously generated in a physical layer from a physical layer to an ATM layer in an ATM communication device, comprising: When the signal indicating the first byte of the valid ATM cell data in the UTOPIA interface indicates a significant level, the signal indicating that the received data from the physical layer is invalid is transmitted to the receiving cell continuously. When the signal indicating the first byte of the valid ATM cell data does not indicate a significant level, the signal indicating whether or not the error occurs in the physical layer is transmitted from the physical layer. A continuous cell reception information transfer method, wherein a signal indicating that received data is invalid is directly transferred to an ATM layer. 2. A continuous cell reception information transfer system for transferring information indicating whether received cells are continuously generated in a physical layer from a physical layer device to an ATM layer device in an ATM communication apparatus. The physical layer device selects one of a signal indicating that received data from the physical layer in the UTOPIA interface is invalid and information indicating whether or not received cells are continuously generated. The ATM layer device includes a signal indicating that received data from the physical layer is invalid, and indicating whether or not received cells are continuously generated from the output of the selecting means. A continuous cell reception information transfer system, comprising: reproduction means for reproducing information. 3. The selecting means determines whether or not a reception cell is continuously generated when a signal indicating the first byte of valid ATM cell data in the UTOPIA interface indicates a significant level. When the signal indicating the first byte of valid ATM cell data does not indicate a significant level, the signal indicating that the data received from the physical layer is invalid is selected. The continuous cell reception information transfer system according to claim 2. 4. The reproducing means, when a signal indicating the first byte of valid ATM cell data indicates a significant level, a receiving cell from a signal from the selecting means in the physical layer device. That reproduces information indicating whether or not occurrences occur continuously
When the signal indicating the first byte of the valid ATM cell data does not indicate a significant level, the signal from the selection means in the physical layer device includes:
4. The continuous cell reception information transfer system according to claim 3, further comprising: a second reproducing unit that reproduces a signal indicating that data received from the physical layer is invalid. 5. The first reproducing means is a flip-flop which fetches a signal from a selecting means in a physical layer device by a transmission clock signal, wherein the second reproducing means sets a high level to a first input terminal. When a signal from the selection means in the physical layer device is input to the second input terminal and the signal indicating the first byte of valid ATM cell data does not indicate a significant level, 5. The continuous cell reception information transfer system according to claim 4, wherein said selector is a selector for selecting a signal of said second input terminal.