CN101944989A - Method and device for transmitting isochronous Ethernet - Google Patents
Method and device for transmitting isochronous Ethernet Download PDFInfo
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Abstract
The embodiment of the invention discloses a method and a device for transmitting isochronous Ethernet, relating to the field of communication. For reducing the achievement cost and the difficulty of the isochronous Ethernet and simultaneously improving the synchronization of signals of a host end and a source-end, the invention provides the following technical scheme: under a channel associated clock, decoding parallel data after series-parallel conversion is finished, and carrying out bit width conversion on the decoded data at a certain ratio; and under a transfer network clock, decoding the data after the bit width conversion is finished and carrying out frame encapsulation on the data, and carrying out mapping processing on the data transmitted according to determined effective payloads to be subjected to frame retransmission, wherein the effective payloads are determined according to the following steps: under the channel associated clock, evenly determining the clock period according to a certain ratio, and carrying out summary count as clock summary count within the determined clock period; and under the transfer network clock, determining the effective payloads to be subjected to frame retransmission according to a comparing value of the summary count and the clock summary count.
Description
Technical field
The present invention relates to the communications field, relate in particular to a kind of synchronous ethernet transfer approach and device.
Background technology
Ethernet is positioned asynchronous network mainly towards local area network applications.The bulky grain Ethernet service is applied to carrier class network gradually as FE (Fast Ethernet, Fast Ethernet), GE (Gigabit Ethernet, gigabit Ethernet), 10GE etc.At present, the bandwidth demand of GE is bigger, has become one of mainstream data business.Following carrier class Ethernet application requirements transmits the ability that network possesses the transparent transmission ethernet clock, promptly requires to make up synchronous ethernet.
At present, the transmission standard of GE synchronous ethernet mainly is made up of encapsulation and mapping, wherein, TTT (Timing Transparent Transmission is adopted in encapsulation, clock transparent transmission) mode, AGMP (Asynchronous General Mapping Process, the async-generic mapping is handled) mode is adopted in mapping.Fig. 1 is the theoretical construct figure of GE synchronous ethernet transfer source end.The GE bit stream converts x bit parallel data to via deserializer, simultaneously deserializer export this parallel data with road clock clk, with the clock of clk as first clock zone.X bit parallel data is converted to y bit parallel data, wherein y=x*0.8 after decoding through 8B10B.Y bit parallel data through 64B65B coding and frame encapsulation after, its data rate promotes 75/64 times that encodes preceding for 64B65B, simultaneously will be through the clk of the 75/64 frequency multiplication clock as the second clock territory.Data after the encapsulation are carried out the AGMP mapping after isolating through second asynchronous FIFO, and the AGMP mapping is to finish in adopting the 3rd clock zone that transmits network clocking.AGMP by defining the number that each transmits effective payload data in the frame, determines the position of valid data in current transmission mainly based on Sigma-delta (sigma-Delta) algorithm
In realizing process of the present invention, the inventor finds that there are the following problems at least in the prior art:
75/64 frequency multiplication is generally by PLL or DDS or digital virtual phase-locked loop realization.Wherein, the hardware cost of PLL or DDS is higher, and data virtual phase-locked loop circuit complexity realizes difficulty.
If through the data after 64B65B coding, the frame encapsulation is not to write asynchronous FIFO equably, when AGMP shines upon so, can even variation, the even variation of response data speed exactly according to each effective payload number that transmits in the frame that the remaining data number in this asynchronous FIFO is determined yet.Therefore, the GE signal of the GE signal received of place termination and source end can not keep strict synchronizing characteristics.
Summary of the invention
Embodiments of the invention provide a kind of synchronous ethernet transfer approach and device, can reduce the realization cost and the difficulty of synchronous ethernet, improve the synchronism of the signal of Su Duanyu source end simultaneously.
For achieving the above object, embodiments of the invention adopt following technical scheme:
A kind of synchronous ethernet transfer approach comprises:
The data that receive are gone here and there and changed, obtain parallel data and with the road clock;
Described with the road clock under, the parallel data after string and conversion is decoded, and decoded data are carried out bit width conversion, to improve the bit wide of described decoded data;
Transmitting under the network clocking, the data after bit width conversion are encoded, the data behind the coding are carried out the frame encapsulation, according to effective payload number transmission data of the frame of determining to be passed, and the data of transmission are shone upon processing;
Wherein, determine effective payload number of described frame to be passed according to following steps: a plurality of with the road evenly select in the clock cycle part with the road clock cycle as the counting clock cycle, carry out accumulated counts in the cycle at counting clock, obtain the clock accumulated counts; Under described transmission network clocking, obtain the accumulated counts of the effective payload number that passes frame; Determine effective payload number of frame to be passed according to the comparison value of the accumulated counts of described effective payload number and described clock accumulated counts.
A kind of synchronous ethernet conveyer comprises:
String and converting unit are used for the data that receive are gone here and there and changed, output parallel data and with the road clock;
Decoding unit, be used for the output of described string and converting unit with the road clock under, the parallel data of described string and converting unit output is decoded;
The bit width conversion unit, be used for the output of described string and converting unit with the road clock under, the data after described decoding unit decodes are carried out bit width conversion, to improve bit wide through described decoding unit 202 decoded data;
Coding unit is used for transmitting under the network clocking data after described bit width conversion unit bit width conversion being encoded;
The frame encapsulation unit is used under described transmission network clocking, and the data behind described coding unit coding are carried out the frame encapsulation;
The clock count unit, be used for the output of described string and converting unit a plurality of with the road clock cycle evenly select part with the road clock cycle as the counting clock cycle, carry out accumulated counts in the cycle at counting clock, obtain the clock accumulated counts;
The payload unit that adds up is used for obtaining the accumulated counts of the effective payload number that passes frame under described transmission network clocking;
Comparing unit is used for the add up accumulated counts of effective payload number that the unit obtains and the clock accumulated counts of described clock count unit output of described payload compared;
The payload determining unit is used under described transmission network clocking, determines effective payload number of frame to be passed according to the comparative result of described comparing unit output.
Map unit is used under described transmission network clocking, the data of effective payload number transmission after described frame encapsulation unit frame encapsulation of determining according to described payload determining unit, and the data of transmission are shone upon processing.
Synchronous ethernet transfer approach and device that the embodiment of the invention provides, by decoded data being carried out a certain proportion of bit wide conversion, frequency reducing counting according to clock carries out transfer of data, therefore, can be with cost low and realize being easy to the logic counting circuit to replace cost higher or realize the frequency doubling device of difficulty, and the clock zone that work is used is reduced to 2 by 3, thereby has reduced difficulty and cost that synchronous ethernet is realized.In addition, count in the clock cycle of evenly determining according to a certain percentage, simulated the data of the TTT encapsulation output characteristic after homogenized, and by this counting relatively with passed the accumulated counts of effective payload number of frame, make the variation of the effective payload number that transmits frame more even, therefore, can transmit the clock characteristic of signal better, the signal that the place end is recovered is easy to keep good synchronizing characteristics with the source end, thereby improves the synchronism of the signal of Su Duanyu source end.
Description of drawings
In order to be illustrated more clearly in the technical scheme of the embodiment of the invention, the accompanying drawing of required use is done an introduction simply in will describing embodiment below, apparently, accompanying drawing in describing below only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.
A kind of synchronous ethernet conveyer structural representation that Fig. 1 provides for the embodiment of the invention;
The structure chart of the GE synchronous ethernet source end that Fig. 2 provides for the embodiment of the invention.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the invention, the technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment that is obtained under the creative work prerequisite.
In order to reduce the realization cost and the difficulty of synchronous ethernet, improve the synchronism of the signal of Su Duanyu source end simultaneously, the embodiment of the invention provides a kind of synchronous ethernet transfer approach, comprising:
101, the data that receive are gone here and there and change, obtain parallel data and with the road clock;
In embodiments of the present invention, the data of reception can be GE bit stream, 10GE bit stream etc.
For example, when the source termination is received the GE bit stream, this GE bit stream is gone here and there and is changed, obtain x bit parallel data and this parallel data with road clock clk.
102, described with the road clock under, the parallel data after string and conversion is decoded, and decoded data are carried out bit width conversion, to improve the bit wide of decoded data.
In this step, when the data that the source termination is received are different bit stream such as GE bit stream, 10GE bit stream, parallel data is carried out corresponding different decoding.
For example, under with road clock clk, x bit parallel data is carried out the 8B10B decoding, be converted to z bit parallel data, wherein, z=x*0.8.And parallel data is carried out ratio is 1: 2 bit width conversion, and the bit wide of this parallel data is improved into original twice.In other alternate embodiments, the ratio of bit width conversion is not limited to 1: 2, also can be other ratio values.
103, transmitting under the network clocking, the data after bit width conversion are encoded, the data behind the coding are carried out the frame encapsulation, and transmit data, data are shone upon processing according to effective payload number of the frame of determining to be passed.
At this, described " frame to be passed " is meant the next frame when the frame of forward direction map unit transmission.In addition, all were to the frame of map unit transmission before hereinafter described " having passed frame " was meant current time, and it comprises the frame when the transmission of forward direction map unit.Hereinafter, will work as the frame of forward direction map unit transmission, be called " present frame ".
In this step, when the data that the source termination is received are different bit stream such as GE bit stream, 10GE bit stream, parallel data is carried out corresponding different coding.
For example, transmitting under the network clocking, z bit parallel data is being carried out the 64B65B coding, and the parallel data behind the coding is carried out the frame encapsulation.In embodiments of the present invention, when the data that the source termination is received are the GE bit stream, adopt TTT (Timing Transparent Transmission, clock transparent transmission) mode to realize encapsulation.Adopt the TTT encapsulation, only allow the number of Superblock (super group code piece) to get 1 during the frame encapsulation, and do not allow to add FCS (Frame Check Sequence, FCS), in addition, ban use of management frames and IDLE (free time) frame.
After parallel data being carried out frame encapsulation, transmit this parallel data according to effective payload number of the frame of determining to be passed, and this parallel data is carried out AGMP (Asynchronous GeneralMapping Process, the async-generic mapping is handled) mapping handle.Wherein, AGMP by defining the number that each transmits effective payload data in the frame, determines the location map of valid data in current transmission mainly based on Sigma-delta (sigma-Delta) algorithm.In addition, adaptive between data rate and container speed is to be finished by AGMP.
Wherein, the step of effective payload number of described definite described frame to be passed comprises:
103a, a plurality of with the road evenly select in the clock cycle part with the road clock cycle as the counting clock cycle, carry out accumulated counts in the cycle at counting clock, obtain the clock accumulated counts;
Wherein, the counting clock cycle is the clock cycle of selecting according to a certain percentage that is used for accumulated counts.The ratio that evenly definite counting clock cycle accounted for the road clock cycle is that the ratio that changes in data rate and bit width conversion adopted of basis before frame encapsulates the back and encodes calculates.More specifically, in embodiments of the present invention, described definite counting clock cycle accounts for ratio with the road clock cycle and equals the product that data rate after the frame encapsulation promotes multiplying power and bit width conversion ratio.For example, when the GE synchronous ethernet transmitted, the data rate after the frame encapsulation promoted to 75/64 times before the coding, and the bit width conversion ratio is decided to be 1: 2, determined evenly that then the ratio in counting clock cycle is 75/ (64*2), and just 75/128.After determining that the counting clock cycle accounts for ratio with the road clock cycle, proportionally selecting uniformly in the clock cycle with the road clock cycle with the road, such as, in embodiments of the present invention, this ratio is 75/128, molecule is become 1 just 1/ (128/75), obtain 1/ (1.7) at last, that is to say and whenever will determine a counting clock cycle with the road clock cycle through 1.7.
In the present embodiment, when calculating the clock accumulated counts, with 0 is that accumulated counts is carried out on the basis, in other words, first counting clock carry out in the cycle 0 with the addition calculation of stated number A, in second counting clock carries out addition for the first time in the cycle result of calculation and the addition calculation of stated number A, carry out the result of calculation of the addition second time and the addition calculation of stated number A in the cycle at the 3rd counting clock, and the like, constantly carry out the result of calculation of last addition and the addition calculation of stated number A.
For example, under with road clock clk, carrying out 75/128 frequency reducing evenly counts, promptly in 128 clock cycle, evenly select 75 clock cycle with road clock clk, these 75 clock cycle are the counting clock cycle, all add 1 accumulated counts (supposing that setting A is 1) in cycle at these 75 counting clocks each counting clock in the cycle, obtain clock accumulated counts T.Specifically, suppose that current clock accumulated counts is T1, if current with the road clock cycle be counting clock during the cycle, current clock accumulated counts T1 is added 1 calculates, obtain new clock accumulated counts T2.In addition, the single of accumulated counts value added (stated number A) is not limited to 1, also can be other numerical value such as 2,3.
103b, under described transmission network clocking, obtain the accumulated counts of the effective payload number that passes frame, according to the accumulated counts of the described effective payload number that has passed frame and the magnitude relationship of described clock accumulated counts, obtain effective payload number of frame to be passed by effective payload number of present frame.Wherein, when the accumulated counts of the effective payload number that passes frame equals the clock accumulated counts, with effective payload number of present frame effective payload number as frame to be passed; When the accumulated counts value of the effective payload number that passes frame the time, with the minimizing value of effective payload number of present frame effective payload number as frame to be passed greater than the clock accumulated counts; When the accumulated counts value of the effective payload number that passes frame the time, with the increase value of effective payload number of present frame effective payload number as frame to be passed less than the clock accumulated counts.
For example, transmitting under the network clocking, reading the accumulated counts of the effective payload number that passes frame of storage
Count C with effective payload of present frame
nWherein, present frame is when being transferred to first Frame of map unit, and effective payload number of present frame can also can be preestablished by the associative operation administrative staff by factory setting.Then, to the accumulated counts of the effective payload number that passes frame that reads
The clock accumulated counts T that evenly counts to get compares, and obtains effective payload number of frame to be passed:
A) exist
The time, with C
nEffective payload as frame to be passed is counted C
N+1
B) exist
The time, with C
n-1 counts C as effective payload of frame to be passed
N+1
C) exist
The time, with C
n+ 1 counts C as effective payload of frame to be passed
N+1
As mentioned above, exist
Or
The time, to C
nAdd 1 or subtract 1 and calculate, and with the effective payload number of result of calculation as frame to be passed.But, also can
Or
The time, to C
nThe plus-minus that carries out other numerical value calculates, and for example, adds 2 or subtract 2 calculating, with the effective payload number of result of calculation as frame to be passed.
Determined that according to the method described above effective payload of frame to be passed counts C
N+1After, effective payload of this frame to be passed is counted C
N+1Accumulated counts with the effective payload number that passes frame that reads
Addition obtains the accumulated counts of the new effective payload number that passes frame
Store the accumulated counts of this new effective payload number that passes frame
To be used for determining effective payload number of next frame to be passed.
The synchronous ethernet transfer approach that the embodiment of the invention provides, by decoded data being carried out a certain proportion of bit wide conversion, frequency reducing counting according to clock carries out transfer of data, therefore, can be with cost low and realize being easy to the logic counting circuit to replace cost higher or realize the frequency doubling device of difficulty, and, need not through 75/64 frequency multiplication with the road clock under work, the clock zone that work is used is reduced to 2 by 3, thereby has reduced difficulty and cost that synchronous ethernet is realized.In addition, count in the clock cycle of evenly determining according to a certain percentage, simulated the data of the TTT encapsulation output characteristic after homogenized, and by this counting relatively with passed the accumulated counts of effective payload number of frame, make the variation of the effective payload number that transmits frame more even, therefore, can transmit the clock characteristic of signal better, the signal that the place end is recovered is easy to keep good synchronizing characteristics with the source end, thereby improves the synchronism of the signal of Su Duanyu source end.
With said method accordingly, the embodiment of the invention also provides a kind of synchronous ethernet conveyer, as shown in Figure 1, comprising:
String and converting unit 201 are used for the data that receive are gone here and there and changed, output parallel data and with the road clock;
Decoding unit 202, be used for 201 outputs of described string and converting unit with the road clock under, the parallel data of described string and converting unit 201 outputs is decoded;
Bit width conversion unit 203, be used for 201 outputs of described string and converting unit with the road clock under, to carrying out bit width conversion, to improve bit wide through described decoding unit 202 decoded data through described decoding unit 202 decoded data;
The payload unit 207 that adds up is used for obtaining the accumulated counts of the effective payload number that passes frame under described transmission network clocking;
Comparing unit 208 is used for the add up accumulated counts of effective payload number that unit 207 obtains and the clock accumulated counts of described clock count unit output of described payload compared;
Further, when the data of described string and converting unit reception are the gigabit Ethernet bit stream,
Described decoding unit 202, specifically be used for 201 outputs of described string and converting unit with the road clock under, the parallel data of described string and converting unit 201 outputs is carried out the 8B10B decoding;
Described bit width conversion unit 203, specifically be used for 201 outputs of described string and converting unit with the road clock under, be 1: 2 bit width conversion to carry out ratio through described decoding unit 202 decoded data;
Described coding unit 204 specifically is used for transmitting under the network clocking, and the data after described bit width conversion unit 203 bit width conversion are carried out the 64B65B coding;
Described clock count unit 206 specifically was used for evenly selecting 75 clock cycle in 128 clock cycle with the road clock of described string and converting unit 201 outputs, as the counting clock cycle; Carry out the current clock accumulated counts and the addition calculation of stated number in cycle at each counting clock, obtain new clock accumulated counts;
Described map unit 210 specifically is used under described transmission network clocking, and to after the encapsulation of described frame encapsulation unit 205 frames, the data of effective payload numbers transmission of determining according to described payload determining unit 209 are carried out the async-generic mapping and handled.
Further, described payload determining unit 209 specifically is used for transmitting under the network clocking, when the accumulated counts of the effective payload number that passes frame equals the clock accumulated counts, with effective payload number of present frame effective payload number as frame to be passed; When the accumulated counts value of the effective payload number that passes frame the time, with the minimizing value of effective payload number of present frame effective payload number as frame to be passed greater than the clock accumulated counts; When the accumulated counts value of the effective payload number that passes frame the time, with the increase value of effective payload number of present frame effective payload number as frame to be passed less than the clock accumulated counts.
Further, the described payload unit 207 that adds up specifically is used to calculate and store the accumulated counts of the effective payload number that passes frame of current storage and effective payload of the frame to be passed that described payload determining unit is determined and counts sum.
Further, described synchronous ethernet conveyer also comprises:
Asynchronous first in first out unit, be used for 201 outputs of described string and converting unit with the road clock under receive the data of described bit width conversion unit 203 outputs, and transmit data to coding unit 204 transmitting under the network clocking.
Further, described synchronous ethernet conveyer also comprises:
The first in first out unit is used for transmitting under the network clocking synchronously, receives the data that described frame encapsulation unit 205 transmits, and effective payload number of determining according to described payload determining unit 209 transmits data to described map unit.
The synchronous ethernet conveyer that the embodiment of the invention provides, by decoded data being carried out a certain proportion of bit wide conversion, frequency reducing counting according to clock carries out transfer of data, therefore, can be with cost low and realize being easy to the logic counting circuit to replace cost higher or realize the frequency doubling device of difficulty, and the clock zone that work is used is reduced to 2 by 3, thereby has reduced difficulty and cost that synchronous ethernet is realized.In addition, count in the clock cycle of evenly determining according to a certain percentage, simulated the data of the TTT encapsulation output characteristic after homogenized, and by this counting relatively with passed the accumulated counts of effective payload number of frame, make the variation of the effective payload number that transmits frame more even, therefore, can transmit the clock characteristic of signal better, the signal that the place end is recovered is easy to keep good synchronizing characteristics with the source end, thereby improves the synchronism of the signal of Su Duanyu source end.
Fig. 2 is the structure chart of GE synchronous ethernet transfer source end.Wherein, first clock zone is represented respectively with 2 different clock zones of road clock zone and transmission network clocking territory with the second clock zone.The GE bit stream is converted to x bit parallel data through behind the deserializer by serial bit stream, simultaneously, deserializer output parallel data with road clock clk.X bit parallel data is converted to z bit parallel data (z=x*0.8) after the 8B10B decoding.Parallel data is carried out parallel data being write asynchronous FIFO (First In First Out, first in first out) after ratio is 1: 2 bit width conversion.And from the parallel data that asynchronous FIFO is read, directly enter and transmit the network clocking territory, in this clock zone, carry out 64B65B coding, frame encapsulation after, write synchronization fifo.
In addition, when parallel data being carried out 1: 2 bit width conversion, carry out 75/128 even counting under with road clock clk, promptly in 128 clock cycle, evenly select 75 clock cycle.In each cycle of these 75 clock cycle choosing, all add 1 accumulation calculating.This calculated value is directly sent into comparator, with the accumulated counts of the effective payload number that passes frame
Compare.According to comparison value, the effective payload that determines each to transmit frame is counted C
i
Synchronization fifo is counted C according to effective payload of every frame
i, to the C of this frame of AGMP mapping transmission
iIndividual data.The AGMP mapping is shone upon processing to the data that receive.
Compared with prior art, after the 8B10B decoding, increased ratio and be 1: 2 bit wide conversion, thereby making greater than 1 75/64 frequency multiplication operational transition is 75/128 frequency reducing counting operation, therefore, replaces frequency doubling device by the logic counting circuit and realizes that synchronous ethernet transmits, and then reduced the cost that technology realizes, simultaneously, clock zone is reduced to 2 by 3, has reduced the difficulty that technology realizes.And, 75/128 even counting has been simulated the data of the TTT encapsulation output characteristic after homogenized, can make the variation of the effective payload number that transmits frame more even, transmit the clock characteristic of GE signal better, the GE signal that the place end is recovered is easy to keep good synchronizing characteristics with the source end.
The field those of ordinary skill is appreciated that all or part of flow process that realizes in the foregoing description method, be to instruct relevant hardware to finish by computer program, described program can be stored in the computer read/write memory medium, this program can comprise the flow process as the embodiment of above-mentioned each side method when carrying out.Wherein, described storage medium can be magnetic disc, CD, read-only storage memory body (Read-Only Memory, ROM) or at random store memory body (Random Access Memory, RAM) etc.
The above; only be the specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; can expect easily changing or replacing, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion by described protection range with claim.
Claims (10)
1. a synchronous ethernet transfer approach is characterized in that, comprising:
The data that receive are gone here and there and changed, obtain parallel data and with the road clock;
Described with the road clock under, the parallel data after string and conversion is decoded, and decoded data are carried out bit width conversion, to improve the bit wide of described decoded data;
Transmitting under the network clocking, the data after bit width conversion are encoded, the data behind the coding are carried out the frame encapsulation, according to effective payload number transmission data of the frame of determining to be passed, the data of transmission are shone upon processing;
Wherein, determine effective payload number of described frame to be passed according to following steps: a plurality of with the road evenly select in the clock cycle part with the road clock cycle as the counting clock cycle, carry out accumulated counts in the cycle at counting clock, obtain the clock accumulated counts; Under described transmission network clocking, obtain the accumulated counts of the effective payload number that passes frame; According to the accumulated counts of described effective payload number and the magnitude relationship of described clock accumulated counts, obtain effective payload number of frame to be passed by effective payload number of present frame.
2. synchronous ethernet transfer approach according to claim 1 is characterized in that, described parallel data after string and conversion is decoded, and decoded data are carried out a certain proportion of bit width conversion comprises:
When data are the gigabit Ethernet bit stream, the parallel data after string and conversion is carried out 8B10B decoding, and decoded data are carried out ratio is 1: 2 bit width conversion;
Described data after bit width conversion are encoded, the data behind the coding are carried out the frame encapsulation, and comprise shining upon to handle according to the data of effective payload number transmission of the frame of determining to be passed:
When data are the gigabit Ethernet bit stream, the data after bit width conversion are carried out 64B65B encode, the data behind the coding are carried out the frame encapsulation, and the data that the effective payload number according to the frame of determining to be passed transmits are carried out the async-generic mapping handle;
In described evenly definite counting clock cycle according to a certain percentage, carry out accumulated counts in the cycle at described counting clock and comprise:
In described 128 clock cycle, evenly select 75 clock cycle, as the counting clock cycle with the road clock; Carry out the current clock accumulated counts and the addition calculation of stated number in cycle at each counting clock, obtain new clock accumulated counts.
3. synchronous ethernet transfer approach according to claim 1 and 2, it is characterized in that, described according to the accumulated counts of described effective payload number and the magnitude relationship of described clock accumulated counts, effective payload number that the effective payload number by present frame obtains frame to be passed comprises:
When the accumulated counts of the effective payload number that passes frame equals the clock accumulated counts, with effective payload number of present frame effective payload number as frame to be passed;
When the accumulated counts value of the effective payload number that passes frame the time, with the minimizing value of effective payload number of present frame effective payload number as frame to be passed greater than the clock accumulated counts;
When the accumulated counts value of the effective payload number that passes frame the time, with the increase value of effective payload number of present frame effective payload number as frame to be passed less than the clock accumulated counts.
4. synchronous ethernet transfer approach according to claim 1 is characterized in that, described according to described effective payload number accumulated counts and the comparison value of described clock accumulated counts determine frame to be passed effective payload number after comprise:
Calculate and store the accumulated counts of described effective payload number and count sum, as the stored counts of the effective payload number that passes frame with effective payload of the frame of determining to be passed;
The described accumulated counts of obtaining the effective payload number that passes frame comprises:
Obtain the accumulated counts of the effective payload number that passes frame of described storage.
5. a synchronous ethernet conveyer is characterized in that, comprising:
String and converting unit are used for the data that receive are gone here and there and changed, output parallel data and with the road clock;
Decoding unit, be used for the output of described string and converting unit with the road clock under, the parallel data of described string and converting unit output is decoded;
The bit width conversion unit, be used for the output of described string and converting unit with the road clock under, the data after described decoding unit decodes are carried out a certain proportion of bit width conversion, to improve the bit wide of the data after described decoding unit decodes;
Coding unit is used for transmitting under the network clocking data after described bit width conversion unit bit width conversion being encoded;
The frame encapsulation unit is used under described transmission network clocking, and the data behind described coding unit coding are carried out the frame encapsulation;
The clock count unit, be used for the output of described string and converting unit a plurality of with the road clock cycle evenly select part with the road clock cycle as the counting clock cycle, carry out accumulated counts in the cycle at counting clock, obtain the clock accumulated counts;
The payload unit that adds up is used for obtaining the accumulated counts of the effective payload number that passes frame under described transmission network clocking;
Comparing unit is used for the add up accumulated counts of effective payload number that the unit obtains and the clock accumulated counts of described clock count unit output of described payload compared;
The payload determining unit is used for the comparative result according to described comparing unit output, obtains effective payload number of frame to be passed by effective payload number of present frame;
Map unit is used under described transmission network clocking, according to the data of effective payload number transmission after described frame encapsulation unit frame encapsulation that described payload determining unit is determined, the data of transmission is shone upon processing.
6. synchronous ethernet conveyer according to claim 5 is characterized in that, when the data of described string and converting unit reception are the gigabit Ethernet bit stream,
Described decoding unit, specifically be used for the output of described string and converting unit with the road clock under, the parallel data of described string and converting unit output is carried out the 8B10B decoding;
Described bit width conversion unit, specifically be used for the output of described string and converting unit with the road clock under, it is 1: 2 bit width conversion that the data after described decoding unit decodes are carried out ratio;
Described coding unit specifically is used for transmitting under the network clocking, and the data after described bit width conversion unit bit width conversion are carried out the 64B65B coding;
Described clock count unit specifically was used for evenly selecting 75 clock cycle in 128 clock cycle with the road clock of described string and converting unit output, as the counting clock cycle; Carry out the current clock accumulated counts and the addition calculation of stated number in cycle at each counting clock, obtain new clock accumulated counts;
Described map unit specifically is used under described transmission network clocking, and to after the encapsulation of described frame encapsulation unit frame, the data of effective payload number transmission of determining according to described payload determining unit are carried out the async-generic mapping and handled.
7. according to claim 5 or 6 described synchronous ethernet conveyers, it is characterized in that, described comparative result according to the output of described comparing unit, effective payload number that the effective payload number by present frame obtains frame to be passed comprises:
When the accumulated counts of the effective payload number that passes frame equals the clock accumulated counts, with effective payload number of present frame effective payload number as frame to be passed;
When the accumulated counts value of the effective payload number that passes frame the time, with the minimizing value of effective payload number of present frame effective payload number as frame to be passed greater than the clock accumulated counts;
When the accumulated counts value of the effective payload number that passes frame the time, with the increase value of effective payload number of present frame effective payload number as frame to be passed less than the clock accumulated counts.
8. synchronous ethernet conveyer according to claim 5, it is characterized in that, the described payload unit that adds up specifically is used to calculate and store the accumulated counts of the effective payload number that passes frame of current storage and effective payload of the frame to be passed that described payload determining unit is determined and counts sum.
9. synchronous ethernet conveyer according to claim 5 is characterized in that, also comprises:
Asynchronous first in first out unit, be used for the output of described string and converting unit with the road clock under receive the data of described bit width conversion unit output, and transmit data to coding unit transmitting under the network clocking.
10. synchronous ethernet conveyer according to claim 5 is characterized in that, also comprises:
The first in first out unit is used for transmitting under the network clocking synchronously, receives the data that described frame encapsulation unit transmits, and transmits data according to effective payload number that described payload determining unit is determined to described map unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010284881 CN101944989A (en) | 2010-09-17 | 2010-09-17 | Method and device for transmitting isochronous Ethernet |
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| CN 201010284881 CN101944989A (en) | 2010-09-17 | 2010-09-17 | Method and device for transmitting isochronous Ethernet |
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| CN101944989A true CN101944989A (en) | 2011-01-12 |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103037222A (en) * | 2012-12-04 | 2013-04-10 | 中国北方车辆研究所 | Compression transmission device and method of parallel digital video signal |
| CN107453939A (en) * | 2017-06-15 | 2017-12-08 | 西安微电子技术研究所 | A kind of time triggered Ethernet solidification point parallel monitoring devices and methods therefor |
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| CN1770636A (en) * | 2004-11-04 | 2006-05-10 | 华为技术有限公司 | Combined coder and combined decoder |
| CN1960231A (en) * | 2005-10-31 | 2007-05-09 | Ut斯达康通讯有限公司 | Multichannel multiplex transmission method and system for CPRI link |
| CN101051879A (en) * | 2007-04-06 | 2007-10-10 | 华为技术有限公司 | Method and device for multiplying and de-multiplying low speed service |
| CN101155006A (en) * | 2006-09-30 | 2008-04-02 | 华为技术有限公司 | Method and apparatus for fixed velocity service transmission |
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| CN1770636A (en) * | 2004-11-04 | 2006-05-10 | 华为技术有限公司 | Combined coder and combined decoder |
| CN1960231A (en) * | 2005-10-31 | 2007-05-09 | Ut斯达康通讯有限公司 | Multichannel multiplex transmission method and system for CPRI link |
| CN101155006A (en) * | 2006-09-30 | 2008-04-02 | 华为技术有限公司 | Method and apparatus for fixed velocity service transmission |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103037222A (en) * | 2012-12-04 | 2013-04-10 | 中国北方车辆研究所 | Compression transmission device and method of parallel digital video signal |
| CN107453939A (en) * | 2017-06-15 | 2017-12-08 | 西安微电子技术研究所 | A kind of time triggered Ethernet solidification point parallel monitoring devices and methods therefor |
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