JP2004110507A - Crossbar large scale integrated circuit, link adjusting method for it, and crossbar network - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crossbar LSI, a link adjusting method for it, and a crossbar network for minimizing lowering of performance by simultaneously performing the adjusting operation for the crossbar LSI at a plurality of spots. <P>SOLUTION: When an adjusting timing detection circuit 603 detects that the value of a timer counter 601 reaches a designated value, or when an adjustment detecting circuit 604 detects the receipt of an adjust signal from an adjacent crossbar LSI, a ling adjustment directive signal is output. The adjusting circuits 608 to 611 of the respective ports generate an adjustment pattern (an adjust signal) and transmit the same to the output parts 7 to 10 of the respective ports on receiving the link adjustment directive signal. The output parts 7 to 10 of the respective ports transmit the adjust signal to the adjacent crossbar LSI prior to the transaction from a relay processing part 5. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a crossbar LSI (Large Scale Integrated Circuit), a link adjustment method thereof, and a crossbar network, and more particularly, to a crossbar LSI for sensing adjustment of an adjacent crossbar LSI and concentrating an adjustment period of the entire network, a link adjustment method thereof, and a crossbar network. About.
[0002]
[Prior art]
In order to connect many processors, a large crossbar needs to be configured. However, in order to construct a large crossbar, it is general to interconnect small small bar LSIs in view of cost and configuration variation. .
[0003]
In a large-scale crossbar (crossbar network), the number of crossbar LSIs connected to each other increases, and it is difficult to use the same CLK source for mounting, and each LSI operates with an asynchronous clock.
[0004]
Furthermore, a serial high-frequency I / F (interface) is used to improve the throughput between the crossbar LSIs, but this interface requires periodic adjustment operations in consideration of temperature changes and skew. And Furthermore, in an asynchronous interface, this adjustment cycle is significantly shorter than in a synchronous interface.
[0005]
FIG. 4 is a configuration example of a crossbar network. Referring to FIG. 4, X1 to X8 are crossbar LSIs, and A to H are processors. Each crossbar LSI is connected by a link that needs to be adjusted periodically.
[0006]
If a route from A to X1 to X2 to X3 to X4 to X8 to H is used when sending a transaction from the processor A to the processor H, the link from A to H passes six times.
[0007]
Assuming that the link unit needs to be adjusted every 5000T and it takes 50T during the adjustment period, the loss due to the adjustment operation when sending a transaction from the processor A to the processor H is 50T × 6 links / 5000T, which is 6%. Results in losses. Assuming that the adjustment cycle = C, the adjustment time = t, and the number of passing crossbar LSIs = n, the above is generally expressed as loss = t × (n + 1) / C × 100 [%]. As is clear from the equation, the loss increases as n increases. Further, the adjustment cycle C is significantly shorter in the case of the asynchronous I / F than in the case of the synchronous I / F. These are disadvantageous in terms of performance when a large number of inexpensive LSIs are connected to form a crossbar.
[0008]
FIG. 5 is a diagram showing a configuration of a conventional crossbar LSI. A conventional crossbar LSI generally operates as follows.
[0009]
Normally, a transaction is received from the port 0 input unit 11 to the port 3 input unit 14, relay processing is performed by the relay processing unit 15, and the transaction is transmitted from the port 0 output unit 17 to the port 3 output unit 20. The timer counter 161 of the link adjusting unit 16 counts up by the +1 circuit 162 for each CLK (clock).
[0010]
When the value of the timer counter 161 reaches a predetermined value, the adjustment timing detection circuit 163 outputs an adjustment instruction to the adjustment circuits of each port (port 0 adjustment circuit 164 to port 3 adjustment circuit 167). An adjustment pattern is generated and output to the port output unit, and the port output unit is instructed to transmit the adjustment pattern. The output unit (port 0 output unit 17 to port 3 output unit 20) of each port transmits the adjustment pattern to the port input unit of the next-stage crossbar LSI, and the port input unit of the next-stage crossbar LSI receives the adjustment pattern. Link adjustment (delay line adjustment and buffer buffer adjustment) of the port input unit (refer to FIG. 6. In FIG. 6, only two ports are shown for simplicity of explanation).
[0011]
While the port 0 adjusting circuit 164 to the port 3 adjusting circuit 167 operate, the timer counter 161 is reset and counts up again. With this operation, the crossbar LSI periodically transmits the adjustment pattern to the next-stage crossbar LSI.
[0012]
FIG. 7 is a diagram showing an example of a conventional adjustment time. FIG. 7 is a time chart showing the adjustment time when the above-described route of A → X1 → X2 → X3 → X4 → X8 → H is used. While each crossbar LSI performs its own adjustment, the adjustment period of each crossbar LSI varies and the time required for the adjustment becomes longer.
[0013]
Non-Patent Document 1 describes that a conventional link adjustment method periodically performs re-adjustment between a transmitter and a receiver in data communication between processors.
[0014]
As a conventional link adjustment method, Patent Document 1 describes that a link is tuned between routers configuring a network.
[0015]
[Patent Document 1]
JP 2000-236323 A (page 4-7, FIG. 1)
[Non-patent document 1]
Toshio Tanahashi, 10 outsiders, “A 2 Gb / s 21CH Low-Latency Transceiver Circuit for Inter-Processor Communication”, ISSC 2001 (February 4-8, 2001) Session 4 (High-Digital.
[0016]
[Problems to be solved by the invention]
However, in the above-described conventional technology, since each crossbar LSI performs adjustment independently, there is a problem that the total adjustment time increases and network performance deteriorates.
[0017]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a crossbar LSI which solves the above-described problems, and which simultaneously performs the adjustment operation between the crossbar LSIs at a plurality of locations in a short time so as to minimize the deterioration in performance, a link adjustment method thereof, and a crossbar network. To provide.
[0018]
[Means for Solving the Problems]
The crossbar LSI according to the first invention of the present application receives a transaction or an adjustment signal, sends it to the relay processing unit and the link adjustment unit, and, when receiving the adjustment signal, performs a plurality of port inputs for adjusting the link of its own port input unit. A relay processing unit that performs a relay process when a transaction is input and sends it out to a corresponding port output unit and discards it when an adjustment signal is input, and at a predetermined adjustment timing or the port input A link adjustment unit that generates an adjustment signal when an adjustment signal is input from the unit and sends the adjustment signal to an output unit of each port; and a transaction from the relay processing unit and an adjustment signal from the link adjustment unit. A plurality of port output units for transmitting an adjustment signal prior to the transaction.
[0019]
The crossbar LSI according to the second aspect of the present invention is the crossbar LSI according to the first aspect, wherein the transaction and the adjustment signal share one line and are received by the port input unit, and the transaction and the adjustment signal are one line. The data is shared and transmitted from the port output unit.
[0020]
The crossbar LSI according to a third aspect of the present invention is the crossbar LSI according to the first aspect, wherein the transaction and the adjustment signal are separately received at the port input section while separately dividing the line, and the transaction and the adjustment signal are divided separately for the line and The transmission is performed from the port output unit.
[0021]
A link adjustment method for a crossbar LSI according to a fourth invention of the present application is a link adjustment method for a crossbar LSI constituting a crossbar network, wherein a port input unit performs link adjustment when an adjustment signal is received and adjusts the received adjustment signal. The link adjustment instruction signal is output when the adjustment detection circuit detects the adjustment signal or when the adjustment timing detection circuit detects that the value of the timer counter has reached a predetermined value. In response to the link adjustment instruction signal, an adjustment signal is generated and transmitted to a port output unit, and the port output unit transmits the adjustment signal generated by the port adjustment circuit.
[0022]
The link adjustment method of a crossbar LSI according to a fifth aspect of the present invention is the link adjustment instruction signal according to the fourth aspect, wherein the port adjustment circuit generates an adjustment signal and transmits the adjustment signal to a port output unit, and the adjacent crossbar LSI adjusts the link adjustment instruction signal. The adjustment operation is started by detecting the signal, an adjustment signal is generated, and the adjustment signal is suppressed by the output of the adjustment suppression circuit until the adjustment detection circuit detects the adjustment signal again.
[0023]
A crossbar network according to a sixth aspect of the present invention is a crossbar network constituted by connecting a plurality of crossbar LSIs for relaying and transferring data, wherein when a port input unit receives an adjustment signal, it performs link adjustment and adjusts the received adjustment signal. The port adjustment circuit generates an adjustment signal when the adjustment signal is sent to the detection circuit and the adjustment detection circuit detects the adjustment signal, or when the adjustment timing detection circuit detects that the value of the timer counter has reached a predetermined value. Characterized in that crossbar LSIs transmitted from each other are connected to each other.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
In a network composed of a plurality of crossbar LSIs, the network system uses an interface that requires regular adjustment between the crossbar LSIs, and one of the crossbar LSIs enters an adjustment sequence. Then, other crossbar LSIs also sense this, enter an adjustment sequence, and concentrate the adjustment period of the entire network, thereby reducing performance degradation due to interface adjustment.
[0025]
Embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.
[0026]
Referring to FIG. 1, a crossbar LSI according to an embodiment of the present invention includes a port 0 input unit 1, a port 1 input unit 2, a port 2 input unit 3, a port 3 input unit 4, a relay processing unit 5, , A link adjusting unit 6, a port 0 output unit 7, a port 1 output unit 8, a port 2 output unit 9, and a port 3 output unit 10. In this example, four ports are provided, but the number of ports is not limited to four.
[0027]
The port 0 input unit 1 receives data transmitted from the processor or another crossbar LSI, and sends the data to the relay processing unit 5 and the adjustment detection circuit 604 of the link adjustment unit 6 via the reception buffer 101. There are two types of data: a transaction transmitted from the processor or another (previous stage) crossbar LSI and an adjustment signal transmitted from another (previous stage) crossbar LSI. Is transmitted and received on the line. If the data is an adjustment signal, link adjustment (adjustment of delay line for CLK phase adjustment and adjustment of buffer buffer) is performed.
[0028]
The port 1 input unit 2, the port 2 input unit 3, and the port 3 input unit 4 are the same as the port 0 input unit 1.
[0029]
The relay processing unit 5 has a data determination unit, a relay processing unit, and a discarding unit. The data from the port 0 input unit 1 to the port 3 input unit 4 are determined by the data determination unit. If the data is a transaction, the relay processing unit relays the transaction and outputs the corresponding port output unit (port 0 The transaction is transmitted to the selector of the output unit 7 to the port 3 output unit 10). If the data from the port 0 input section 1 to the port 3 input section 4 is an adjustment signal, the adjustment signal is discarded by the discarding means.
[0030]
The link adjustment unit 6 generates an adjustment pattern (adjustment signal) in response to the adjustment request and sends it to the selectors of the output units (port 0 output unit 7 to port 3 output unit 10) of each port. The link adjustment unit 6 includes a timer counter 601, a +1 circuit 602, an adjustment timing detection circuit 603, an adjustment detection circuit 604, an adjustment suppression circuit 605, an OR circuit 606, a circuit 607, and a port 0 adjustment circuit 608. , A port 1 adjustment circuit 609, a port 2 adjustment circuit 610, and a port 3 adjustment circuit 611.
[0031]
The timer counter 601 counts +1 by the +1 circuit 602 for each clock, and is reset when the circuit 607 outputs a link adjustment instruction signal.
[0032]
The adjustment timing detection circuit 603 checks the value of the timer counter 601 and, when detecting the timing required for adjustment (when the value of the timer counter 601 reaches a predetermined value), outputs an adjustment request to the OR circuit 606.
[0033]
The adjustment detection circuit 604 detects that the crossbar LSI connected adjacently has started link adjustment, and instructs adjustment of the own crossbar LSI. That is, when any of the data from the port 0 input unit 1 to the port 3 input unit 4 is an adjustment signal, it recognizes that the adjacent crossbar LSI has started the adjustment operation, and outputs an adjustment request to the OR circuit 606. . If all of the data from the port 0 input unit 1 to the port 3 input unit 4 are not adjustment signals, no adjustment request is output.
[0034]
The outputs of the adjustment timing detection circuit 603 and the adjustment detection circuit 604 are ORed by an OR circuit 606 and then output as a link adjustment instruction signal. The link adjustment instruction signal is suppressed by the output of the adjustment suppression circuit 605 in the circuit 607.
[0035]
The port 0 adjustment circuit 608 generates an adjustment pattern (adjustment signal) and outputs it to the selector 701 of the port 0 output unit 7 when the link adjustment instruction signal is on. An adjustment signal is a signal of a specific pattern that can be clearly distinguished from a transaction.
[0036]
The port 1 adjustment circuit 609, the port 2 adjustment circuit 610, and the port 3 adjustment circuit 611 are similar to the port 0 adjustment circuit 608.
[0037]
The port 0 output unit 7 has a selector 701, and transmits data (transaction or adjustment signal) output from the selector 701 to another (next stage) crossbar LSI. The selector 701 receives the transaction from the relay processing unit 5 and the adjustment signal from the link adjustment unit 6, and outputs the adjustment signal from the link adjustment unit 6 prior to the transaction from the relay processing unit 5. That is, when the adjustment signal from the link adjustment unit 6 is not input, the transaction from the relay processing unit 5 is output, and when the adjustment signal from the link adjustment unit 6 is input, the output of the transaction is temporarily stopped. An adjustment signal from the link adjustment unit 6 is output.
[0038]
The port 1 output unit 8, the port 2 output unit 9, and the port 3 output unit 10 are the same as the port 0 output unit 7.
[0039]
When the link adjustment instruction signal is turned on, the relay transfer of the transaction (reception of the transaction by the port input unit, processing in the relay processing unit 5 and transmission of the transaction by the port output unit) is temporarily suspended, and the adjustment suppression circuit releases the suppression. When this happens, the relay transfer of the transaction resumes.
[0040]
The operation of the embodiment of the present invention will be described in detail with reference to FIG.
[0041]
First, an outline of the operation of the crossbar LSI during normal times (other than the link adjustment operation) will be described. The link adjustment operation (simply referred to as an adjustment operation) includes a link adjustment of the port input unit by receiving the adjustment signal and an adjustment pattern (adjustment signal) of the port adjustment circuit by the output of the link adjustment instruction signal. Refers to transmission from the port output unit.
[0042]
The port 0 input unit 1 to the port 3 input unit 4 receive the transaction from the port output unit of the preceding crossbar LSI, perform the relay processing in the relay processing unit 5, and perform the processing from the port 0 output unit 7 to the port 3 output unit 10 to the next stage. Is transmitted to the port input section of the crossbar LSI. During this time, the timer counter 601 of the link adjusting unit 6 counts up for each CLK.
[0043]
Next, the operation of the link adjusting unit 6 will be described in detail.
[0044]
The adjustment timing detection circuit 603 outputs an adjustment request when the value of the timer counter 601 reaches a predetermined value. When the adjustment detection circuit 604 or the adjustment suppression circuit 605 is not operating, the adjustment request from the adjustment timing detection circuit 603 becomes a LINK adjustment instruction signal and is sent to the adjustment circuits of each port (port 0 adjustment circuit 608 to port 3 adjustment circuit 611). The adjustment circuit (port 0 adjustment circuit 608 to port 3 adjustment circuit 611) of each port generates an adjustment pattern (adjustment signal) and outputs the output of each port (port 0 output section 7 to port 3 output section 10). Output to the selector. While the port 0 adjusting circuit 608 to the port 3 adjusting circuit 611 operate, the timer counter 601 is reset and counts up again. With this operation, the link adjustment unit 6 of the crossbar LSI periodically generates and outputs an adjustment pattern (adjustment signal).
[0045]
On the other hand, when the adjustment detection circuit 604 detects that the adjacent crossbar LSI is performing link adjustment (detects that the data input from the port input unit is an adjustment signal), it outputs an adjustment request. This adjustment request is ORed with the adjustment request from the adjustment timing detection circuit 603 by the OR circuit 606. When the adjustment suppression circuit 605 is not operating, the adjustment request from the adjustment detection circuit 604 becomes a LINK adjustment instruction signal and is output to the adjustment circuits (port 0 adjustment circuit 608 to port 3 adjustment circuit 611) of each port. Therefore, when the adjacent crossbar LSI enters the adjustment operation, the own crossbar LSI can also perform the adjustment operation with a slight difference.
[0046]
The adjustment suppression circuit 605 suppresses the adjustment instruction for a while when the own crossbar LSI enters the link adjustment operation. By doing so, the adjustment operation of the own crossbar LSI causes the adjacent crossbar LSI to start the adjustment operation, thereby preventing a loop of the adjustment instruction such that the own crossbar LSI starts the adjustment operation again due to the influence. The period in which the adjustment suppression circuit 605 suppresses the time until the own crossbar LSI enters an adjustment operation, the adjacent crossbar LSI detects the adjustment, starts adjustment, and the adjustment detection circuit of the own crossbar LSI detects the adjustment. Is set to A timer counter is used to detect the period set in the adjustment suppression circuit 605. When the adjustment suppression circuit reaches a value obtained by adding the above-mentioned time to the reset value of the timer counter, the suppression is canceled, and the operation becomes normal.
[0047]
Further description will be made with reference to FIG. FIG. 2 is a diagram illustrating the link adjustment operation. FIG. 2 illustrates a part of the crossbar network for simplicity of description, and each crossbar LSI illustrates only two ports.
[0048]
(1) Assume that the timer counter of the second crossbar LSI reaches a predetermined value, issues an adjustment request, and outputs a link adjustment instruction. Then, the adjustment circuit of each port of the second crossbar LSI generates an adjustment pattern (adjustment signal).
[0049]
(2) The adjustment pattern (adjustment signal) is transmitted from the output unit of each port of the second crossbar LSI to the adjacent crossbar LSI.
[0050]
(3) The port 0 input section of the first crossbar LSI and the port 1 input section of the third crossbar LSI receive an adjustment pattern (adjustment signal) and perform link adjustment.
[0051]
(4) The first crossbar LSI and the third crossbar LSI detect the adjustment operation of the adjacent crossbar LSI (second crossbar LSI) and output a link adjustment instruction, and the adjustment circuit of each port generates an adjustment pattern.
[0052]
(5) An adjustment pattern (adjustment signal) is transmitted from an output unit of each port of the first crossbar LSI and the third crossbar LSI to an adjacent crossbar LSI.
[0053]
(6) The port 1 input section of the second crossbar LSI, the port 0 input section of the second crossbar LSI, and the port 1 input section of the fourth crossbar LSI receive an adjustment pattern (adjustment signal) and perform link adjustment.
[0054]
{Circle around (7)} The fourth crossbar LSI detects an adjustment operation of the adjacent crossbar LSI (third crossbar LSI) and outputs a link adjustment instruction, and the adjustment circuit of each port generates an adjustment pattern. The second crossbar LSI detects the adjustment signals of the adjacent crossbar LSIs (the first crossbar LSI and the third crossbar LSI), but does not output the link adjustment instruction because the adjustment suppression circuit operates.
[0055]
(8) The adjustment pattern (adjustment signal) is transmitted from the output unit of each port of the fourth crossbar LSI to the adjacent crossbar LSI.
[0056]
(9) The port 0 input section of the third crossbar LSI receives the adjustment pattern (adjustment signal) and performs link adjustment.
[0057]
In this way, the adjacent crossbar LSI performs link adjustment in a chained manner. Therefore, the link adjustment period of the crossbar LSI configuring the crossbar network can be concentrated.
[0058]
FIG. 3 shows the adjustment time when the present invention is applied. FIG. 3 shows an adjustment time in the same case as in FIG. 6 described in the related art. Although there is a difference in the time when the adjustment timing propagates to the crossbar LSI, the adjustment timing is almost simultaneously executed, so that the performance degradation is minimized.
[0059]
Next, another embodiment of the present invention will be described.
[0060]
In the above embodiment, the adjustment detection circuit is provided in the LINK adjustment unit. However, as another embodiment, an adjustment detection circuit is provided in each input unit of each port, and the output of each adjustment detection circuit is provided in the link adjustment unit. May be input to the OR circuit. In the present embodiment, since the adjustment signal is detected by the port input unit, the adjustment signal is not sent to the relay processing unit, and the adjustment signal does not need to be discarded by the relay processing unit, so that the relay processing unit can be simplified.
[0061]
Further, in the above-described embodiment, one port is provided between the port input unit of the own crossbar LSI and the port output unit of another crossbar LSI and between the port output unit of the own crossbar LSI and the port input unit of the other crossbar LSI. Although a transaction and an adjustment signal are flowing on this line, another embodiment is described between the port input unit of the own crossbar LSI and the port output unit of the other crossbar LSI and the crossbar LSI of the own crossbar LSI. The port output unit and the port input unit of another crossbar LSI may be connected by two lines, one of which may be a transaction line and the other may be an adjustment signal line. In the present embodiment, since the lines for the transaction and the adjustment signal are separate, there is an effect that the pattern of the adjustment signal is not restricted.
[0062]
【The invention's effect】
The effect of the present invention is that, when a plurality of crossbar LSIs are periodically connected by a link that requires an adjustment operation, a period in which a transaction across the plurality of crossbar LSIs cannot operate during link adjustment is reduced, and performance degradation due to the adjustment operation is reduced. It is to reduce to the minimum.
[0063]
The reason is that a means for detecting the link adjustment operation of the adjacent crossbar LSI, performing a self-link adjustment operation, and transmitting an adjustment signal to the adjacent crossbar LSI is provided, and the link adjustment period conventionally performed independently is set. This is because they are related to each other and concentrated in a short period of time.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an embodiment of the present invention; FIG. 2 is a diagram illustrating a link adjusting operation of the present invention; FIG. 3 is a diagram showing an adjusting time of the present invention; FIG. FIG. 5 is a diagram illustrating a configuration of a conventional crossbar LSI. FIG. 6 is a diagram illustrating a conventional link adjustment operation. FIG. 7 is a diagram illustrating a conventional adjustment time.
1 Port 0 input unit 2 Port 1 input unit 3 Port 2 input unit 4 Port 3 input unit 5 Relay processing unit 6 Link adjustment unit 7 Port 0 output unit 8 Port 1 output unit 9 Port 2 output unit 10 Port 3 output unit 11 port 0 input unit 14 Port 3 input unit 15 Relay processing unit 16 Link adjustment unit 17 Port 0 output unit 20 Port 3 output unit 101 Receive buffer 161 Timer counter 162 +1 circuit 163 Adjustment timing detection circuit 164 Port 0 adjustment circuit 167 Port 3 adjustment circuit 601 Timer counter 602 +1 circuit 603 Adjustment timing detection circuit 604 Adjustment detection circuit 605 Adjustment suppression circuit 606 OR circuit 607 circuit 608 Port 0 adjustment circuit 609 Port 1 adjustment circuit 610 Port 2 adjustment circuit 611 Port 3 adjustment circuit 701 Select

Claims (6)

A plurality of port input units that receive a transaction or an adjustment signal and send the adjustment signal to the relay processing unit and the link adjustment unit and adjust the link of the own port input unit when the adjustment signal is received;
A relay processing unit that performs a relay process when a transaction is input and sends it to a corresponding port output unit and discards when an adjustment signal is input;
A link adjustment unit that generates an adjustment signal and sends it to an output unit of each port at each predetermined adjustment timing or when an adjustment signal is input from the port input unit;
A plurality of port output units that receive a transaction from the relay processing unit and an adjustment signal from the link adjustment unit and transmit the adjustment signal in preference to the transaction,
A crossbar LSI comprising: The transaction and the adjustment signal are received by the port input unit by sharing one line, and the transaction and the adjustment signal are transmitted by the port output unit by sharing one line. The crossbar LSI according to claim 1. 2. The apparatus according to claim 1, wherein the transaction and the adjustment signal are separately received at the port input section while separating the line, and the transaction and the adjustment signal are separately transmitted from the port output section while separating the line. Crossbar LSI. A method for adjusting a link of a crossbar LSI constituting a crossbar network, comprising:
Upon receiving the adjustment signal, the port input unit performs link adjustment and sends the received adjustment signal to the adjustment detection circuit,
When the adjustment detection circuit detects the adjustment signal or when the adjustment timing detection circuit detects that the value of the timer counter has reached a predetermined value, it outputs a link adjustment instruction signal,
The port adjustment circuit receives the link adjustment instruction signal, generates an adjustment signal, and sends it to the port output unit.
The port output unit transmits an adjustment signal generated by the port adjustment circuit,
A link adjustment method for a crossbar LSI. The link adjustment instruction signal is generated by the port adjustment circuit and the port output unit transmits the adjustment signal. The adjacent crossbar LSI detects the adjustment signal and starts an adjustment operation to generate an adjustment signal. 5. The crossbar LSI link adjustment method according to claim 4, wherein the adjustment is suppressed by an output of the adjustment suppression circuit until the detection circuit detects the adjustment signal. A crossbar network configured by connecting a plurality of crossbar LSIs for relaying and transferring data,
When the port input unit receives the adjustment signal, it performs link adjustment and sends the received adjustment signal to the adjustment detection circuit. If the adjustment detection circuit detects the adjustment signal, or the adjustment timing detection circuit sets the timer counter to a predetermined value. A crossbar network comprising: a crossbar LSI configured to mutually connect a crossbar LSI that generates an adjustment signal and transmits from a port output unit when the port adjustment circuit detects that the adjustment has occurred.

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