WO2012001753A1

WO2012001753A1 - Access control device

Info

Publication number: WO2012001753A1
Application number: PCT/JP2010/006810
Authority: WO
Inventors: 石井宏明
Original assignee: パナソニック株式会社
Priority date: 2010-06-28
Filing date: 2010-11-19
Publication date: 2012-01-05

Abstract

During transmission, if a period during which a packet is not transmitted is equal to or longer than a predetermined time period, a terminal switch unit (205) is controlled by a transmission request detection unit (202), an LPI control unit (203), a comparison unit (206), and a setting unit (207), so as to make a physical layer device (100) to a power saving mode. During reception, when a flow control frame is received, if the stop time information contained in the frame requests stopping for equal to or more than a predetermined time period, electric power control is performed so that electric power control can be performed without damaging communication performance. Further, when the flow control frame is received, if a flag contained in the frame is set, the physical layer device remains in the low power consumption mode after the transmission stop time has passed, so as to perform effective electric power control.

Description

Access control device

The present invention relates to an access control device, and more particularly to a technology for suppressing power consumption of a communication device via a network.

With the spread of the Internet, there are an increasing number of personal computers and digital home appliances used at home having a network interface connected to the Internet. Interfaces of these devices include wired or wireless interfaces, and wired networks that comply with the IEEE 802.3 standard and wireless networks that comply with the IEEE 802.11 standard are widely used.

Focusing on the LAN (Local Area Network) of wired networks, the communication speed of personal computers and digital home appliances used at home has been generally 10 Mbps or 100 Mbps so far, but in recent years, higher speed Gigabit LANs have become widespread. ing. In order to realize high-speed communication, communication between a physical (PHY) layer device and a MAC (Media Access Control) layer device performed at 25 MHz when communicating via MII (Media Independent Interface) at 100 Mbps. In the gigabit LAN, the signal is transferred at 125 MHz via GMII (Gigabit Media Independent Interface). For this reason, power consumption for each terminal has been increased along with an increase in operation speed.

According to Non-Patent Document 1, a method for performing flow control by communication between LAN terminals is defined. Specifically, when the flow control frame is received, the transmission stop time is extracted by the QUANTA extraction unit. Thereafter, when the normal reception detection unit detects that the flow control frame has been correctly received, the non-transmission detection unit confirms that the transmission operation is not performed, and then the transmission control unit stops the transmission operation. Thereafter, when only the stop time elapses, the transmission control unit resumes the transmission operation.

On the other hand, as a power reduction method in the conventional access control apparatus, a method of reducing power by reducing the power of the reception system circuit when not receiving has been proposed. According to this method, for example, at the time of wireless LAN communication, since the reception timing of the beacon transmitted from the master is known in advance, the reception system circuit can be stopped when the data is not received by itself. Was able to drop. However, since these networks are premised on the presence of a terminal serving as a master, it is difficult to perform the same control in a LAN where this terminal does not exist.

Further, in Patent Document 1, while receiving instructions from the other terminal to stop transmission to the own terminal by transmitting a flow control frame to the other terminal and suppressing transmission to the own terminal, reception of the own terminal Attempts have been made to shut down the system.

Furthermore, in Patent Document 2, when a plurality of communication traffic flows through one port, there is a method of performing logical flow control for each stream by logically embedding traffic identification information in a flow control frame. Proposed.

International Publication No. 2008/032750 JP 2003-224574 A

Now, in the conventional wired network, power was not actively controlled because power was always supplied to each terminal. For this reason, there has been a situation in which the physical layer device continues to waste power even when packets are not transmitted or while transmission is stopped due to flow control. Although it has been a problem that has occurred in the past, in recent years when communications have started at gigabit speeds, there has been a great increase in the amount of wasted power, and countermeasures have to be taken.

Therefore, in the IEEE 802.3az standard, an interface between a physical layer device and a MAC layer device for putting the physical layer device into a low power state is defined, and the MAC layer device instructs the physical layer device to control power. For example, when the communication rate is not so high, the physical layer device can be dynamically changed to a low power state. However, on the other hand, under what conditions power control should be performed is undefined, and a control method for achieving both communication performance and power consumption reduction is required.

An object of the present invention is to detect a free time during non-communication and to control the power of a physical layer device connected to the outside while considering the time required for recovery, thereby reducing the power saving function without losing the communication band. Is to realize.

To achieve the above object, in the transmission system, a transmission data storage unit that temporarily stores transmission data, a transmission unit that outputs data to the physical layer device, and a transmission stacked in the transmission data storage unit A transmission control unit that converts packets into a form that can be transmitted to the network and transmits them, a reception data storage unit that temporarily stores packets received from the network, a reception unit that inputs data from the network, and a network input A reception control unit that converts data so that data can be stored in the reception data storage unit, a QUANTA extraction unit that extracts a transmission stop time included in the frame when a flow control frame is received, and a flow control frame correctly A normal reception detection unit that detects the completion of reception and a transmission control unit that detects when normal reception is detected. In addition to the conventional configuration including an untransmitted detection unit that detects that it is not in a state, a transmission data absence period measuring timer detected by the transmission request detecting unit, and a predetermined time from completion of packet transmission in the timer When the transmission rate is high by providing an LPI (Low Power Idle) control unit that instructs the physical layer device to transition to the low power state when it is detected that there is no next transmission packet during the period Since the timing at which data starts to be accumulated in the transmission data storage unit is before the timer expires, the transition to the low power state of the physical layer device by the LPI control unit is not performed. When the transmission rate is not so high, the timer expires before the next packet starts to be accumulated in the transmission data storage unit, and instructs the LPI control unit to transition the physical layer device to the low power state.

Furthermore, in the reception system, in addition to the conventional configuration, a timer for measuring the transmission stop time extracted by the QUANTA extraction unit when the flow control frame is received, and a comparison for determining that the flow control time is a certain value or more And a PAUSE threshold value setting unit that holds a value to be compared, and an LPI control unit that instructs the physical layer device to transition between a low power state and a normal communication state. When the comparison unit determines that the extracted time is larger than the value instructed by the PAUSE threshold setting unit, and determines that the extracted time should be changed to the low power state, the physical layer device is set to the low power state with respect to the LPI control unit. Instruct to make a transition.

The LPI control unit includes, for example, a state management unit and a timer. When the LPI control unit receives a request for transition to the LPI control state by the LPI control signal, the state management unit transitions to the LPI state and validates the terminal switching control signal. Further, the terminal switching unit changes the terminal state and sets the terminal state to a low power state defined by the physical layer device. When receiving a return request from the LPI control state, the terminal switching control signal is invalidated, and the terminal switching unit returns the terminal state to the normal communication state. At this time, the terminal is in a normal communication state. When the state management unit returns to the normal communication state, a timer is started, and control is performed so as not to transition to the low power state again until a predetermined time. By doing so, power control of the physical layer device can be stably performed.

According to the present invention, the power consumption of the physical layer device can be reduced when it is not necessary to transmit a packet in the transmission system, and the physical layer device can be used even when transmission is stopped in response to reception of a flow control frame in the reception system. Power consumption can be reduced without degrading communication performance.

It is a block diagram which shows the structure of the access control apparatus which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the structure of the access control apparatus which concerns on the 2nd Embodiment of this invention. It is a conceptual diagram which shows the example of a flow control frame. It is a figure which shows the detailed structural example of an LPI control part. It is a block diagram which shows the structure of the access control apparatus which concerns on the 3rd Embodiment of this invention. It is a conceptual diagram which shows the example of an extended flow control frame.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<< First Embodiment >>
FIG. 1 is a configuration diagram of an access control apparatus according to the first embodiment of the present invention. In FIG. 1, 100 is a physical (PHY) layer device, 101 is a transmission data storage unit, 102 is a transmission unit, 103 is a transmission control unit, 104 is a reception data storage unit, 105 is a reception unit, 106 is a reception control unit, 107 Is a non-transmission detection unit, 108 is a normal reception detection unit, 109 is a QUANTA extraction unit, 201 is a timer, 202 is a transmission request detection unit, 203 is an LPI control unit, 204 is a terminal switching control signal, 205 is a terminal switching unit, 206 Is a comparison unit, and 207 is a setting unit.

The access control device in FIG. 1 is capable of temporarily transmitting data input in a form having a certain bus width and transmitting the data stored in the transmission data storage unit 101 to an external network. A transmission control unit 103 that transmits frames at intervals of a predetermined period or longer, a transmission request detection unit 202 that detects that data to be transmitted does not exist in the transmission data storage unit 101, A timer 201 that measures a period in which no transmission data exists in the transmission data storage unit 101, a setting unit 207 that presets a waiting time for causing the physical layer device 100 to transition to a low power state, and the waiting time has elapsed. A comparison unit 206 that determines that the physical layer device 100 and the MAC when the comparison unit 206 determines that the waiting time has elapsed. It comprises a terminal switching portion 205 to change the state of the interface between the device and a LPI controller 203 to instruct so as to shift the physical layer device 100 to the low power state.

The comparison unit 206 transitions the physical layer device 100 to the low power state when it detects that there is no data transmission request during the minimum interframe gap (IFG) defined in the IEEE 802.3 standard after frame transmission is completed. Alternatively, when the comparison unit 206 detects that there is no data transmission request during the startup time (Tw_sys) of the physical layer device 100 defined by the IEEE 802.3az standard after completion of frame transmission, the comparison unit 206 reduces the physical layer device 100 to a low level. Transition to the power state. Alternatively, the comparison unit 206 causes the physical layer device 100 to transition to the low power state when there is no transmission request during the waiting time instructed by the setting unit 207. After returning the physical layer device 100 from the low power state, the LPI control unit 203 lowers the physical layer device 100 again during the start-up time (Tw_sys) of the physical layer device 100 defined by the IEEE 802.3az standard. Do not transition to power state.

As the transmission data storage unit 101, a FIFO (First-In / First-Out) type memory is generally used. The FIFO is composed of a write pointer indicating a data write position, a read pointer indicating a data read position, and a storage area for storing data. When the FIFO is empty and no data is written, the read pointer and the write pointer are at the same position. When transmitting a packet, each word is written to the FIFO one by one. When one word is written to the FIFO from the beginning of the packet, the write pointer moves to a position indicating the next write position. When the second word is written, the write pointer advances further. By repeating this, the entire transmission packet is written into the FIFO. When there is a part or all of the packet to be transmitted in the FIFO, the transmission control unit 103 starts transmitting the packet and transmits the packet data in the FIFO. When packet transmission is started, data is read out one word at a time by the transmission unit 102, and the read pointer advances to the next reading position in order.

When the transmission is completed, a transmission completion notification is transmitted from the transmission control unit 103 to the transmission request detecting unit 202, and the positions of the write pointer and the read pointer of the FIFO again match, and the FIFO is empty. This is notified to the transmission request detection unit 202.

When the transmission request detection unit 202 receives the transmission completion notification and the notification that the FIFO is empty, it instructs the timer 201 to start measuring time. When the time measurement is started in the timer 201, the comparison unit 206 performs a coincidence comparison with the stop time value set in the setting unit 207 configured by a register. The comparison result is notified to the transmission request detection unit 202. When the comparison results match, the transmission request detection unit 202 notifies the LPI control unit 203 of the low power state transition request of the physical layer device 100.

When the LPI control unit 203 receives the low power state transition request of the physical layer device 100, the terminal switching control signal 204 is validated and a low power state in which the physical layer device 100 defines the terminal state is specified to the terminal switching unit 205. Fix as shown.

In addition, when the LPI control unit 203 enables the terminal switching control signal 204, if data starts to be loaded into the FIFO, the write pointer advances, so the comparison result between the read pointer and the write pointer becomes inconsistent, The transmission request detection unit 202 is notified that the FIFO is no longer empty. When notified that the FIFO is not empty, the transmission request detection unit 202 notifies the LPI control unit 203 of a request for returning the physical layer device 100 from the low power state. The LPI control unit 203 invalidates the terminal switching control signal 204, cancels the control by the terminal switching unit 205, and returns the terminal state to the normal communication state.

As described above, according to this embodiment, the power consumption of the physical layer device 100 can be reduced when it is not necessary to transmit a packet in the transmission system.

<< Second Embodiment >>
FIG. 2 is a configuration diagram of an access control apparatus according to the second embodiment of the present invention. In FIG. 2, 100 is a physical layer device, 101 is a transmission data storage unit, 102 is a transmission unit, 103 is a transmission control unit, 104 is a reception data storage unit, 105 is a reception unit, 106 is a reception control unit, and 107 is not transmitted. Detection unit, 108 normal reception detection unit, 109 QUANTA extraction unit, 203 LPI control unit, 204 terminal switching control signal, 205 terminal switching unit, 301 timer, 302 comparison unit, 303 PAUSE threshold setting unit It is.

The access control apparatus of FIG. 2 can store input data in a form having a certain bus width when data input from the interface between the physical layer device 100 and the MAC layer device is not a flow control frame. A reception control unit 106 for conversion, a reception data storage unit 104 for storing data output from the reception control unit 106, and data input from an interface between the physical layer device 100 and the MAC layer device are flow control frames. The QUANTA extraction unit 109 that extracts the transmission stop time included in the flow control frame, the normal reception detection unit 108 that detects that the flow control frame has been normally received, and the flow control frame is correctly received. An unsent detector 107 that detects that the sending side is in an unsent state when it can be done. A PAUSE threshold value setting unit 303 that selects a transmission stop period threshold value in advance, a comparison unit 302 that compares the transmission stop time extracted by the QUANTA extraction unit 109 with the threshold value selected by the PAUSE threshold value setting unit 303, and the comparison unit When it is determined in 302 that the physical layer device 100 is to be shifted to the low power state, the LPI control unit 203 that instructs the physical layer device 100 to transition to the low power state and the physical layer device 100 are set to the low power state. And a timer 301 for measuring the period of transition.

The comparison unit 302 instructs the LPI control unit 203 to transition to the low power state when the transmission stop time extracted by the QUANTA extraction unit 109 is a value other than 0. Alternatively, when the transmission stop time extracted by the QUANTA extraction unit 109 is equal to or greater than the output value of the PAUSE threshold setting unit 303, the comparison unit 302 causes the LPI control unit 203 to switch the physical layer device 100 to the low power state. Instruct a transition.

FIG. 3 shows a flow control frame 601 defined in Non-Patent Document 1. When the elements constituting the flow control frame 601 are listed from the top of the frame, 602 is a destination address (DA), 603 is a source address (SA), 604 is a control frame identifier, 605 is a flow control frame identifier, and 606 is stopped. Time (PAUSE TIME) 607 is a frame check sequence (FCS) for confirming the consistency of the flow control frame 601.

When the reception of the flow control frame 601 is started, the QUANTA extraction unit 109 extracts the transmission stop time 606. Thereafter, when reception up to the frame check sequence 607 is completed, the FCS of the received frame is calculated based on the FCS calculation method stipulated in Non-Patent Document 1, and the comparison with the FCS value included in the received frame is performed by the normal reception detection unit 108. If they match, it is determined that the reception was successful. When the comparison is completed, the non-transmission detection unit 107 detects that the transmission control unit 103 is not transmitting, and notifies the transmission control unit 103 of a flow control request. At this time, the transmission stop time 606 extracted by the QUANTA extraction unit 109 is also set for the timer 301, and the comparison unit 302 is notified of the execution of the comparison. When the comparison unit 302 is notified of the execution of the comparison, the value input from the PAUSE threshold value setting unit 303 is compared with the value of the timer 301, and the value set in the timer 301 is the PAUSE threshold value setting unit 303. When the value is greater than or equal to the value input from, the low power state transition request of the physical layer device 100 is notified to the LPI control unit 203. When the LPI control unit 203 receives the low power state transition request of the physical layer device 100, the terminal switching control signal 204 is validated and a low power state in which the physical layer device 100 defines the terminal state is specified to the terminal switching unit 205. Fix as shown. When the count of the time set in the timer 301 expires, the comparison unit 302 notifies the LPI control unit 203 of a request to return the physical layer device 100 from the low power state. The LPI control unit 203 invalidates the terminal switching control signal 204, cancels the control by the terminal switching unit 205, and returns the terminal state to the normal communication state.

FIG. 4 is a detailed configuration diagram of the LPI control unit 203 in the first and second embodiments. In FIG. 4, 203 is an LPI control unit, 401 is an LPI control signal, 402 is an LPI state management unit, 403 is a timer, 204 is a terminal switching control signal, and 205 is a terminal switching unit.

When the LPI control signal 401 instructs the physical layer device 100 to transition to the power saving mode, the LPI state management unit 402 makes a transition from the clock-on state to the LPI state and enables the terminal switching control signal 204. Thus, the terminal switching unit 205 changes the terminal state to the LPI state. Further, when the physical layer device 100 is instructed to return from the power saving mode by the LPI control signal 401, the control transitions from the LPI state to the clock-on state, the terminal switching control signal 204 becomes invalid, and the terminal switching unit The terminal state is returned to the normal state by 205. At this time, time is measured by the timer 403 so that the physical layer device 100 does not transition to the LPI state again until the recovery from the power saving state is completed.

As described above, according to the present embodiment, the power consumption of the physical layer device 100 can be reduced without degrading the communication performance even when transmission is stopped after receiving the flow control frame in the reception system.

<< Third Embodiment >>
FIG. 5 is a configuration diagram of an access control apparatus according to the third embodiment of the present invention. In FIG. 5, 100 is a physical layer device, 101 is a transmission data storage unit, 102 is a transmission unit, 103 is a transmission control unit, 104 is a reception data storage unit, 105 is a reception unit, 106 is a reception control unit, and 107 is not transmitted. Detection unit, 108 normal reception detection unit, 109 QUANTA extraction unit, 203 LPI control unit, 204 terminal switching control signal, 205 terminal switching unit, 301 timer, 302 comparison unit, 303 PAUSE threshold setting unit , 501 are flag detection units.

The access control apparatus in FIG. 5 can store input data in a form having a certain bus width when data input from the interface between the physical layer device 100 and the MAC layer device is not a flow control frame. A reception control unit 106 for conversion, a reception data storage unit 104 for storing data output from the reception control unit 106, and data input from an interface between the physical layer device 100 and the MAC layer device are flow control frames. The QUANTA extraction unit 109 that extracts the transmission stop time included in the flow control frame, the normal reception detection unit 108 that detects that the flow control frame has been normally received, and the flow control frame is correctly received. An unsent detector 107 that detects that the sending side is in an unsent state when it can be done. A PAUSE threshold value setting unit 303 that selects a transmission stop period threshold value in advance, a comparison unit 302 that compares the transmission stop time extracted by the QUANTA extraction unit 109 with the threshold value selected by the PAUSE threshold value setting unit 303, and the comparison unit When it is determined in 302 that the physical layer device 100 is to be shifted to the low power state, the LPI control unit 203 that instructs the physical layer device 100 to transition to the low power state and the physical layer device 100 are set to the low power state. A timer 301 that measures a transition period and a flag detection unit 501 that extracts a flag included in the flow control frame when the flow control frame is received.

The comparison unit 302 maintains the low power state of the physical layer device 100 with respect to the LPI control unit 203 even after completion of time measurement in the timer 301 when the flag detection unit 501 detects a flag in the received flow control frame. Instruct. In addition, when the flag detection unit 501 does not detect the flag when receiving the flow control frame, the comparison unit 302 stops the transmission of the physical layer device 100 after stopping the transmission stop time extracted by the QUANTA extraction unit 109. Instructs the return from the normal state to the normal transmission state.

FIG. 6 shows an extended flow control frame 701 that is uniquely defined by extending the flow control frame 601 defined in Non-Patent Document 1 uniquely. In addition to each element constituting the flow control frame 601, a flag (FLAG) 702 is newly defined.

When reception of the extended flow control frame 701 is started, the transmission stop time 606 is extracted by the QUANTA extraction unit 109. After that, the flag detection unit 501 extracts the flag 702, and when the reception is completed up to the frame check sequence 607, the FCS of the received frame is calculated based on the FCS calculation method defined in Non-Patent Document 1, and is included in the received frame. Comparison with the FCS value is performed in the normal reception detection unit 108, and if they match, it is determined that normal reception has been achieved. When the comparison is completed, the non-transmission detection unit 107 detects that the transmission control unit 103 is not transmitting, and notifies the transmission control unit 103 of a flow control request. At this time, the transmission stop time 606 extracted by the QUANTA extraction unit 109 and the flag 702 extracted by the flag detection unit 501 are also notified to the timer 301 to the timer 301. When the comparison unit 302 is notified of the execution of the comparison, the value input from the PAUSE threshold value setting unit 303 is compared with the value of the timer 301, and the value set in the timer 301 is the PAUSE threshold value setting unit 303. When the value is greater than or equal to the value input from, the low power state transition request of the physical layer device 100 is notified to the LPI control unit 203. When the LPI control unit 203 receives the low power state transition request of the physical layer device 100, the terminal switching control signal 204 is validated and a low power state in which the physical layer device 100 defines the terminal state is specified to the terminal switching unit 205. Fix as shown. Also, the transmission control unit 103 is instructed to stop transmission. When the count of the time set in the timer 301 expires, the comparison unit 302 confirms whether the flag 702 is set.

When the flag is set, the comparison unit 302 does not notify the LPI control unit 203 of a return request from the low power state of the physical layer device 100. In the LPI control unit 203, the terminal switching control signal 204 remains valid, and the transmission control unit 103 remains instructed to stop transmission. Thereafter, when the flow control frame is received again, if the flag is not set and the transmission stop time 606 extracted by the QUANTA extraction unit 109 indicates 0, the LPI control unit in the comparison unit 302 203 notifies the physical layer device 100 of a return request from the low power state. The LPI control unit 203 invalidates the terminal switching control signal 204, cancels the control by the terminal switching unit 205, and returns the terminal state to the normal communication state. If the transmission stop time 606 extracted by the QUANTA extraction unit 109 indicates a value other than 0 even though the flag is not set, the timer 301 counts the transmission stop time 606 and then the comparison unit 302 The LPI control unit 203 is notified of a return request from the low power state of the physical layer device 100. The LPI control unit 203 invalidates the terminal switching control signal 204, cancels the control by the terminal switching unit 205, and returns the terminal state to the normal communication state.

On the other hand, if the flag is not set, the LPI control unit 203 is notified of a request to return the physical layer device 100 from the low power state. The LPI control unit 203 invalidates the terminal switching control signal 204, cancels the control by the terminal switching unit 205, and returns the terminal state to the normal communication state.

As described above, according to the present embodiment, when the flag included in the frame is set when the flow control frame is received, the physical layer device 100 is stopped in the low power consumption mode even after the transmission stop time has elapsed. Thus, efficient power control can be performed.

As described above, by installing the access control device of the present invention in a digital home appliance that is required to have low power consumption, power consumption when the device is not communicating or when the device is not operating Can be reduced. Further, according to the present invention, even in a personal computer, it is possible to reduce power when there is no communication.

DESCRIPTION OF SYMBOLS 100 Physical (PHY) layer device 101 Transmission data storage part 102 Transmission part 103 Transmission control part 104 Reception data storage part 105 Reception part 106 Reception control part 107 Untransmission detection part 108 Normal reception detection part 109 QUANTA extraction part 201 Timer 202 Transmission request Detection unit 203 LPI control unit 204 Terminal switching control signal 205 Terminal switching unit 206 Comparison unit 207 Setting unit 301 Timer 302 Comparison unit 303 PAUSE threshold setting unit 401 LPI control signal 402 LPI state management unit 403 Timer 501 Flag detection unit 601 Flow control frame 602 Destination address 603 Source address 604 Control frame identifier 605 Flow control frame identifier 606 Transmission stop time 607 Frame check sequence 701 Extended flow control frame 702

Claims

An accumulator that temporarily stores data input in a form having a certain bus width;
A transmission control unit that converts the data stored in the storage unit so that it can be transmitted to an external network, and transmits frames at intervals of a predetermined period; and
A transmission request detection unit for detecting that data to be transmitted does not exist in the storage unit;
A timer for measuring a period in which transmission data does not exist in the storage unit when not transmitted;
A setting unit that presets a waiting time for transitioning the physical layer device to the low power state;
A comparator for determining that the waiting time has elapsed;
A terminal switching unit that changes a state of an interface between the physical layer device and the MAC layer device when it is determined that a waiting time has elapsed in the comparison unit;
An access control apparatus comprising: an LPI control unit that instructs the physical layer device to transition to a low power state.
The access control apparatus according to claim 1.
The comparison unit transitions the physical layer device to a low power state when it detects that there is no data transmission request during the minimum interframe gap defined by the IEEE 802.3 standard after completion of frame transmission. Access control device.
The access control apparatus according to claim 1.
The comparison unit causes the physical layer device to transition to a low power state when it detects that there is no data transmission request during the start-up time of the physical layer device specified by the IEEE 802.3az standard after frame transmission is completed. An access control device.
The access control apparatus according to claim 1.
The comparison unit causes the physical layer device to transition to a low power state when there is no transmission request during the waiting time instructed by the setting unit.
The access control apparatus according to claim 1.
The LPI control unit, after returning the physical layer device from the low power state, does not transition the physical layer device to the low power state again during the start-up time of the physical layer device defined by the IEEE 802.3az standard. An access control device.
A reception control unit that converts the input data so that it can be stored in a form having a certain bus width when the data input from the interface between the physical layer device and the MAC layer device is not a flow control frame;
A reception data storage unit for storing data output from the reception control unit;
A QUANTA extraction unit that extracts a transmission stop time included in the flow control frame when data input from an interface between the physical layer device and the MAC layer device is a flow control frame;
A normal reception detector that detects that the flow control frame has been successfully received;
An unsent detector that detects that the sending side is in an unsent state when the flow control frame has been correctly received;
A PAUSE threshold value setting unit for selecting a threshold value for the transmission stop period in advance;
A comparison unit that compares the transmission stop time extracted in the QUANTA extraction unit with the threshold selected in the PAUSE threshold setting unit;
An LPI control unit for instructing transition of the physical layer device to a low power state when the comparison unit determines to transition the physical layer device to a low power state;
An access control apparatus comprising: a timer for measuring a period during which the physical layer device is transitioned to a low power state.
The access control apparatus according to claim 6.
The comparison unit instructs the LPI control unit to transition to a low power state of the physical layer device when the transmission stop time extracted by the QUANTA extraction unit is a value other than 0. Access control device.
The access control apparatus according to claim 6.
When the transmission stop time extracted by the QUANTA extraction unit is equal to or greater than the output value of the PAUSE threshold setting unit, the comparison unit causes the LPI control unit to make a transition to the low power state of the physical layer device. An access control device characterized by instructing.
A reception control unit that converts the input data so that it can be stored in a form having a certain bus width when the data input from the interface between the physical layer device and the MAC layer device is not a flow control frame;
A reception data storage unit for storing data output from the reception control unit;
A QUANTA extraction unit that extracts a transmission stop time included in the flow control frame when data input from an interface between the physical layer device and the MAC layer device is a flow control frame;
A normal reception detector that detects that the flow control frame has been successfully received;
An unsent detector that detects that the sending side is in an unsent state when the flow control frame has been correctly received;
A PAUSE threshold value setting unit for selecting a threshold value for the transmission stop period in advance;
A comparison unit that compares the transmission stop time extracted in the QUANTA extraction unit with the threshold selected in the PAUSE threshold setting unit;
An LPI control unit for instructing transition of the physical layer device to a low power state when the comparison unit determines to transition the physical layer device to a low power state;
A timer for measuring a period of transition of the physical layer device to a low power state;
An access control apparatus comprising: a flag detection unit that extracts a flag included in the flow control frame when the flow control frame is received.
The access control device according to claim 9, wherein
When the comparison unit detects a flag in the received flow control frame at the flag detection unit, the LPI control unit maintains the low power state of the physical layer device even after completion of time measurement in the timer. An access control device characterized by instructing.
The access control device according to claim 9, wherein
The comparison unit stops the transmission stop time extracted by the QUANTA extraction unit when the flag detection unit does not detect the flag at the time of flow control frame reception, and then stops from the low power state of the physical layer device. An access control device that instructs to return to a normal transmission state.