CN102769587A - Method and devices for enhancing PCI-E (Peripheral Component Interconnect - Express) data transmission stability - Google Patents

Abstract

The invention provides a method and devices for enhancing PCI-E (Peripheral Component Interconnect - Express) data transmission stability, wherein a PCI-E signal is acquired; the transmission mode of the signal is judged according to the acquired PCI-E signal; in the case of an even mode signal, the preset edge of the even mode signal is used as a time reference point; according to the time reference point, the delay time is calculated; the delay time of the even mode signal is brought forward; the even mode signal of which the delay time is brought forward is output; in the case of a superposing mode signal, the even mode signal and an odd mode signal are separated; the preset edge of the even mode signal is used as the time reference point; according to the time reference point, the delay time is calculated; the delay time of the even mode signal is brought forward; the even mode signal of which the delay time is brought forward and the odd mode signal are combined into a new signal; and the new signal is output. According to the method, two devices are provided. According to the scheme, the signals are separated, and the delay time of the even mode signal is brought forward; the crosstalk is prohibited fundamentally, so that the signal shake caused by the crosstalk is decreased; and therefore, the quality of PCI-E signal transmission is improved.

Description

Strengthen the method and the device of PCI-E data transmission stability

Technical field

The present invention relates to the communications field, particularly relate to a kind of method and device of the PCI-E of enhancing data transmission stability.

Background technology

Present PCI-E (PCI-Express; Up-to-date bus and interface standard) the agreement physical layer adopts is that the high speed serialization line transmits, PCI-E2.0 agreement wherein, every road differential pair transmission speed is up to 5Gbps; And the speed of PCI-E3.0 has reached 8Gbps especially; High signal transmission rate like this, also very high to the signal transfer quality requirement, the delay of several psecs all might cause the signals sampling mistake.Because the raising of data rate, the wiring of printed circuit board (Printed Circuit Board is called for short PCB) and technological design etc. require further to improve, and also need carry out accurate control to the impedance of interconnection line.

Traditional a kind of method is preemphasis and equilibrium.Generally, adopt pre-emphasis technique, increase high fdrequency component, be used for remedying the high fdrequency component of the loss of transmission course through driver at the transmitting terminal of signal.Receiving terminal at signal adopts balancing technique, realizes the compensation to high fdrequency component through the multiplication factor that increases high fdrequency component.The general PCI-E equipment that in FPGA, constitutes all can reach best portfolio effect through the parameter that is provided with of regulating in the equalizer.The application of balancing technique; To improving the PCI-E eye diagram quality certain help is arranged, the eye pattern of open closed again also can increase the amplitude of eye pattern; But in practice, the jitter elimination that balancing technique causes for crosstalking between the high speed signal does not have too big effect basically.

Summary of the invention

Based on this, be necessary can't eliminate the shake of crosstalking and causing to prior art, cause PCI-E transfer of data problem of unstable, a kind of method and device of the PCI-E of enhancing data transmission stability is provided.

A kind of method that strengthens the PCI-E data transmission stability comprises step:

Obtain the PCI-E signal, judge the transmission mode of signal according to the PCI-E signal that obtains;

If even mould mode signal, with the preset edge of even mould mode signal as moment datum mark, according to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, the even mould mode signal of output advance/retard time;

If overlay model signal; Isolate even mould mode signal and Qi Mo mode signal; With the preset edge of even mould mode signal as moment datum mark; According to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, signal and output that the even mould mode signal of advance/retard time is synthetic new with strange mould mode signal.

The method of above-mentioned enhancing PCI-E data transmission stability, having analyzed crosstalks causes the basic reason of shake, separates signal; With the even mould mode signal advance/retard time; Suppress to crosstalk from root, thereby reduce the signal jitter of crosstalking and causing, increased the quality of PCI-E signal transmission.

A kind of device that strengthens the PCI-E data transmission stability comprises:

Mode identificating circuit is used to judge the transmission mode of the PCI-E signal of entering, selects the output signal of signal correcting circuit according to the transmission mode control MUX of signal;

Signal correcting circuit; PCI-E signal to getting into directly separates; With the preset edge of even mould mode signal as moment datum mark; According to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, the even mould mode signal of advance/retard time and the synthetic new signal of strange mould mode signal;

With said mode identificating circuit and the MUX that said signal correcting circuit is connected, be used for judged result according to said mode identificating circuit, when be strange mould mode signal or multiple signals all do not switch signal the time, select original PCI-E signal and output; When being even mould mode signal or overlay model signal, select new signal output.

The device of above-mentioned enhancing PCI-E data transmission stability; Having analyzed crosstalks causes the basic reason of shake provides a kind of signal correcting circuit, separates all signals; With the even mould mode signal advance/retard time; Suppress to crosstalk from root, thereby reduce the signal jitter of crosstalking and causing, increased the quality of PCI-E signal transmission.

A kind of device that strengthens the PCI-E data transmission stability is characterized in that, comprising:

Mode identificating circuit is used to judge the transmission mode of the PCI-E signal of entering, according to the transmission mode control signal correction circuit output signal of signal;

Signal correcting circuit is used for the judged result according to mode identificating circuit, when input signal is strange mould mode signal or multiple signals all during the signal of not saltus step, directly exports the PCI-E signal; When being even mould mode signal, with the preset edge of even mould mode signal as moment datum mark, according to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, the even mould mode signal of output advance/retard time; If overlay model signal; Isolate even mould mode signal and Qi Mo mode signal; With the preset edge of even mould mode signal as moment datum mark; According to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, signal and output that the even mould mode signal of advance/retard time is synthetic new with strange mould mode signal.

The device of above-mentioned enhancing PCI-E data transmission stability; Having analyzed crosstalks causes the basic reason of shake provides a kind of signal correcting circuit, separates the overlay model signal; With the even mould mode signal advance/retard time; Suppress to crosstalk from root, thereby reduce the signal jitter of crosstalking and causing, increased the quality of PCI-E signal transmission.

Description of drawings

Fig. 1 strengthens the principle schematic of the method embodiment of PCI-E data transmission stability for the present invention;

Fig. 2 strengthens the structural representation of PCI-E data transmission stability device embodiment for the present invention;

Fig. 3 is a signal correcting circuit structural representation of the present invention;

Fig. 4 is a parity mode mode signal split circuit structural representation of the present invention;

Fig. 5 is a mode identificating circuit structural representation of the present invention;

Fig. 6 strengthens the structural representation of PCI-E data transmission stability device embodiment for the present invention is another kind of.

Embodiment

Below strengthen the method for PCI-E data transmission stability and each embodiment of device is described in detail to the present invention.

At first describe to the method that strengthens the PCI-E data transmission stability.

Referring to Fig. 1, be the principle schematic that the present invention strengthens the method embodiment of PCI-E data transmission stability,

Step S101: obtain the PCI-E signal, according to the transmission mode of the PCI-E signal judgement signal that obtains, if even mould mode signal gets into step S102, if the overlay model signal gets into step S103;

Step S102: with the preset edge of even mould mode signal as moment datum mark, according to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, the even mould mode signal of output advance/retard time;

Step S103: isolate even mould mode signal and Qi Mo mode signal; With the preset edge of even mould mode signal as moment datum mark; According to the datum mark computing relay time in the moment; With the even mould mode signal advance/retard time, signal and output that the even mould mode signal of advance/retard time is synthetic new with strange mould mode signal.

Preset edge is 50% edge, also can be set at other ratio edges as required, and present embodiment is 50% to introduce with preset value.This programme also comprises step, when being judged as the signal that strange mould mode signal or multiple signals all do not switch, then directly exports the PCI-E signal.

PCI-E transfer of data physical layer is transmitted by differential pair, and every pair of differential pair transmission speed can be up to 8Gbps, and the shake of several psecs all can produce very large influence to signal.Usually in the time of PCB layout, all are the order wire laying modes that adopt alternate positive and negative, also other wire laying modes can be arranged, such as positive and negative negative positive mode.The PCI-E signal of this programme input can be multiple signals.Present embodiment is from the alternate positive and negative wire laying mode, and input two-way PCI-E signal specifically describes.With these two pairs of differential signal lines, promptly 4 coupled transmission lines are analytic target, from the angle that mode is decomposed transmission signals are analyzed.

On the microstrip line of coupling, there are even mould and Qi Mo two states, correspond respectively to the switching mode of both drive signals, wherein, the unit length propagation delay the when propagation delay of unit length is greater than strange mould pattern during even mould pattern.Two drive signal combinations of coupling interconnection line can be divided into 3 types:

(1) homophase saltus step, it is right promptly to form common-mode signal, makes coupling line be in even mould pattern;

(2) anti-phase saltus step, it is right to form differential signal, makes coupling line be in strange mould pattern;

(3) drive signal saltus steps, and another remains unchanged.Can drive signal decomposition with two and become even mold component and strange mold component, these two components are transferred to receiving terminal along lead respectively independently, and this drive group is collectively referred to as overlay model.

In 3 kinds of compound modes of drive signal, Qi Mo equates that with the probability of even mould pattern overlay model is the twice of Qi Mo or even mould pattern.Because the reason of coupled transmission line exists transmission delay in the parity mode, make the shake of signal become big; Simultaneously in the superposed signal pattern, because transmission delay, will cause the changes in amplitude of signal.When overlay model, drive signal can resolve into even mould mode signal and Qi Mo mode signal.Because the interconnection line system is linear, be synthetic by even mould mode signal and Qi Mo mode signal so receive signal.Therefore, can from receive signal, separate unusual mould mode signal and even mould mode signal.In order to revise the time delay and the changes in amplitude of crosstalking and introducing; Can parity mode be separated; 50% edge that receives signal during with overlay model with even mould mode signal advance/retard time △ D, is improved the amplitude distortion and the sequential distortion that receive signal as 0 moment comprehensively.Specific as follows:

After obtaining the PCI-E signal, judge the transmission mode of PCI-E signal, carry out following processing according to transmission mode:

(1) if strange mould mode signal does not process signal, directly exports the PCI-E signal;

(2), 50% edge of even mould mode signal as moment datum mark, according to the datum mark computing relay time in the moment, with even mould mode signal advance/retard time △ D, wherein, is calculated △ D method and is if even mould mode signal:

Select wherein lead, conductor length is l, and self-induction and mutual inductance value are respectively L ₀And L _m, self-capacitance and mutual capacitance are respectively C ₀And C _m, the L in the formula in the strange mould pattern ₀, L _m, C ₀And C _mWith the L in the even mould pattern ₀, L _m, C ₀And C _mIdentical respectively, use D _0ddAnd D _EvenThe propagation delay of representing parity mode respectively is slow, then

$D_{\mathrm{odd}}=l\sqrt{(L_0-L_m)(C_0+C_m)}\≈l\sqrt{L_0{C}_0}(1+\frac{1}{2}(\frac{C_m}{C_0}-\frac{L_m}{L_0}-\frac{L_m{C}_m}{L_0{C}_0}))$

$D_{\mathrm{even}}=l\sqrt{(L_0+L_m)(C_0-C_m)}\≈l\sqrt{L_0{C}_0}(1+\frac{1}{2}(\frac{L_m}{L_0}-\frac{C_m}{C_0}-\frac{L_m{C}_m}{L_0{C}_0}))$

Because the unit length propagation delay the when propagation delay of unit length is greater than strange mould pattern during even mould pattern, i.e. D _0dd<d _Even, order

The total delay time of then strange mould mode signal and even mould mode signal can be represented as follows:

$\mathrm{\&Delta;D}=D_{\mathrm{even}}-D_{\mathrm{odd}}\&ap;l\sqrt{L_0{C}_0}(\frac{L_m}{L_0}-\frac{C_m}{C_0})=l(\frac{L_m}{Z_0}-C_m{Z}_0);$

At last the even mould mode signal of advance/retard time △ D is exported;

(3) if overlay model; Isolate even mould mode signal and Qi Mo mode signal; With 50% edge of even mould mode signal as moment datum mark; According to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, signal and output that the even mould mode signal of advance/retard time is synthetic new with strange mould mode signal.The method of wherein, separating the response of even mould mode signal and Qi Mo mode signal is:

U _S(t)＝U _e(t)+U ₀(t)

U _c(t)＝U _e(t)-U ₀(t)

Wherein, Us (t) and Uc (t) represent the primary signal and the primary signal that keeps steady state of switching state respectively, and these two signals constitute the PCI-E signal.Ue (t) representes even mould mode signal, and Uo (t) representes strange mould mode signal.Divided by 2, can obtain even mould mode signal according to two formula additions, subtract each other divided by 2 according to formula and can obtain strange mould mode signal.

Computing relay time △ D method is:

Select wherein lead, conductor length is l, and self-induction and mutual inductance value are respectively L ₀And L _m, self-capacitance and mutual capacitance are respectively C ₀And C _m, in the formula, the L in the strange mould pattern ₀, L _m, C ₀And C _mWith the L in the even mould pattern ₀, L _m, C ₀And C _mIdentical respectively, use D _0ddAnd D _EvenThe propagation delay of representing parity mode respectively is slow, then

$D_{\mathrm{odd}}=l\sqrt{(L_0-L_m)(C_0+C_m)}\&ap;l\sqrt{L_0{C}_0}(1+\frac{1}{2}(\frac{C_m}{C_0}-\frac{L_m}{L_0}-\frac{L_m{C}_m}{L_0{C}_0}))$

$D_{\mathrm{even}}=l\sqrt{(L_0+L_m)(C_0-C_m)}\&ap;l\sqrt{L_0{C}_0}(1+\frac{1}{2}(\frac{L_m}{L_0}-\frac{C_m}{C_0}-\frac{L_m{C}_m}{L_0{C}_0}))$

Because the unit length propagation delay the when propagation delay of unit length is greater than strange mould pattern during even mould pattern, i.e. D _0dd<d _Even, order

The total delay time of then strange mould mode signal and even mould mode signal can be represented as follows:

$\mathrm{\&Delta;D}=D_{\mathrm{even}}-D_{\mathrm{odd}}\&ap;l\sqrt{L_0{C}_0}(\frac{L_m}{L_0}-\frac{C_m}{C_0})=l(\frac{L_m}{Z_0}-C_m{Z}_0)$

Then revised signal is:

U _S(t)＝U _e(t+△D)+U ₀(t)

U _c(t)＝U _e(t+△D)-U ₀(t)

At last, with revised signal output.

(4) when two paths of signals does not all have saltus step, then directly export signal.

Through different mode is carried out different processing, the shake of signal is controlled in the tolerance interval, suppress to crosstalk from root, thereby reduced the shake of signal.

Strengthen the method for PCI-E data transmission stability according to the invention described above; The present invention provides a kind of enhancing PCI-E data transmission stability device, and Fig. 2 strengthens PCI-E data transmission stability device for the structural representation that the present invention strengthens PCI-E data transmission stability device embodiment through using the present invention; A kind of signal correcting circuit is provided; All Signal Separation Cheng Qimo mode signals and even mould mode signal,, suppress to crosstalk from root with the even mould mode signal advance/retard time; Thereby reduce the signal jitter of crosstalking and causing, increased the quality of PCI-E signal transmission.

A kind of enhancing PCI-E data transmission stability device like Fig. 2, comprising:

Mode identificating circuit 201 is used to judge the transmission mode of the PCI-E signal of entering, selects the output signal of signal correcting circuits 202 according to the transmission mode control MUX 203 of signal;

Signal correcting circuit 202; PCI-E signal to getting into directly separates; With the preset edge of even mould mode signal as moment datum mark; According to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, the even mould mode signal of advance/retard time and the synthetic new signal of strange mould mode signal;

The MUX 203 that is connected with said signal correcting circuit 202 with said mode identificating circuit 201; Be used for judged result according to said mode identificating circuit 201; When be strange mould mode signal or multiple signals all do not switch signal the time, select original PCI-E signal and output; When being even mould mode signal or overlay model signal, select new signal output.

Preset edge is 50% edge, also can be set at other ratio edges as required, and present embodiment is 50% to introduce with preset value.During PCB layout, can adopt the order wire laying mode of alternate positive and negative, also other wire laying modes can be arranged, such as positive and negative negative positive mode.The PCI-E signal of this programme input can be multiple signals.Present embodiment is from the alternate positive and negative wire laying mode, and input two-way PCI-E signal is described.The processing of multiple signals only need increase corresponding correction circuit and selector.

Original PCI-E signal gets into mode identificating circuit 201 and signal correcting circuit 202, and signal correcting circuit directly separates the PCI-E signal and delays time.Referring to Fig. 3, be signal correcting circuit structural representation of the present invention.The signal that no matter gets into is that strange mould mode signal, even mould mode signal, overlay model signal are all isolated even mould mode signal and Qi Mo mode signal; Strange mould mode signal is not processed; With 50% edge of even mould mode signal as moment datum mark; According to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, signal and output that the even mould mode signal of advance/retard time is synthetic new with strange mould mode signal.Signal correcting circuit also comprises the advance/retard module, and the advance/retard module is meant that signal is preposition, is about to even mould mode signal and shifts to an earlier date the time of delay of one-period.Wherein, R _S<<r _Load, R _M<<r _Load

Signal correcting circuit 202 also comprises parity mode mode signal split circuit; Referring to Fig. 4; It is parity mode mode signal split circuit structural representation of the present invention; The primary signal Uc (t) of primary signal Us of switching state (t) and maintenance steady state constitutes the PCI-E signal as a pair of driving source of circuit.When even mould mode signal during, at node A, B place, because of the electromotive force at this two place equates do not have electric current to flow through R as driving source _MSo the primary circuit mid portion is equivalent to open circuit; Work as resistance R _sMuch smaller than load R _LoadThe time, the voltage that node A (or B) locates just equals even mould mode signal.When strange mould mode signal during as driving source, because of electromotive force is opposite, resistance R _MThe centre be equivalent to ground connection; Work as R _MTo such an extent as to very little when being equivalent to zero, be equivalent to short circuit between node A, B place and the ground, promptly strange mould mode signal is equivalent to direct short-circuit to ground.For with Us (t) and Uc (t) during as a pair of driving source of circuit, the signal that node A (or B) locates just has only even mould mode signal Ue (t) so, according to following two formulas,

U _S(t)＝U _e(t)+U ₀(t)

U _c(t)＝U _e(t)-U ₀(t)

Also just obtained strange mould mode signal Uo (t), so the parity mode mode signal is all separated from primary signal.Concrete delay time, synthetic method are identical with the method for above-mentioned enhancing PCI-E data transmission stability, repeat no more at this.

Mode identificating circuit 201 is used to judge the transmission mode of the PCI-E signal of entering, selects the output signal of signal correcting circuits 202 according to the transmission mode control MUX 203 of signal.Referring to Fig. 5, be mode identificating circuit structural representation of the present invention, simultaneously in former and later two positions of different time output, come to the transmission mode that signal is judged in 4 outputs according to two paths of signals.Two signals are respectively a and b among the figure, and former and later two adjacent positions are respectively a ₀With a _l, b ₀With b ₁, according to:

a ₀With a ₁Not homophase, and b ₀With b ₁Not homophase, and a _lWith b ₁Different phase times are strange mould mode signal;

a ₀With a ₁Not homophase, and b ₀With b ₁Same phase time, for A road signal switches, B road signal remains unchanged;

a ₀With a ₁Homophase, and b ₀With b ₁Different phase times, for A road signal remains unchanged, B road signal switches;

a ₀With a ₁Homophase, and b ₀With b ₁Same phase time, two paths of signals all do not switch.

Make following logical formula:

Idol mould mode signal:

Even?Mode=(a ₀?XOR?a ₁)AND(b ₀?XOR?b ₁)AND(a _l?XNOR?b ₁)

Strange mould mode signal:

Odd?Mode=(a ₀XOR?a ₁)AND(b ₀?XOR?b ₁)AND(a _l?XOR?b ₁)

A road signal switches, and B road signal remains unchanged:

A?Switch&B?Constant=(a ₀?XOR?a ₁)AND(b ₀?XNOR?b ₁)

A road signal remains unchanged, and B road signal switches:

A?Constant?＆?B?Switch=(a ₀?XNOR?a ₁)AND(b ₀?XOR?b ₁)

Two paths of signals all remains unchanged:

Both?Constant=(a ₀?XOR?a ₁)XNOR(b ₀?XOR?b ₁)

At any one time, more than to have only the differentiation result of a state in these five logical formulas be 1, other state is 0, has then judged each pattern respectively.

MUX 203 is selected the output of signal correcting circuit 202 according to the judged result of mode identificating circuit 201.When judged result is even mould mode signal, select new signal to export; When judged result is strange mould mode signal, select original PCI-E signal to export; When judged result is that A road signal switches, B road signal remains unchanged or A road signal remains unchanged, and when B road signal switches, selects new signal to export; When two paths of signals all remains unchanged, select original PCI-E signal to export.

Strengthen the method for PCI-E data transmission stability according to the invention described above; The present invention provides the another kind of PCI-E of enhancing data transmission stability device, and Fig. 6 strengthens PCI-E data transmission stability device for the structural representation that the present invention strengthens PCI-E data transmission stability device embodiment through using the present invention; A kind of signal correcting circuit is provided; Separate superposed signal,, suppress to crosstalk from root with the even mould mode signal advance/retard time; Thereby reduce the signal jitter of crosstalking and causing, increased the quality of PCI-E signal transmission.

A kind of enhancing PCI-E data transmission stability device like Fig. 6, comprising:

Mode identificating circuit 601 is used to judge the transmission mode of the PCI-E signal of entering, according to the transmission mode control signal correction circuit output signal of signal;

Signal correcting circuit 602 is used for the judged result according to mode identificating circuit, when input signal is strange mould mode signal or multiple signals all during the signal of not saltus step, directly exports the PCI-E signal; When being even mould mode signal, with the preset edge of even mould mode signal as moment datum mark, according to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, the even mould mode signal of output advance/retard time; If overlay model signal; Isolate even mould mode signal and Qi Mo mode signal; With the preset edge of even mould mode signal as moment datum mark; According to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, signal and output that the even mould mode signal of advance/retard time is synthetic new with strange mould mode signal.

Preset edge is 50% edge, also can be set at other ratio edges as required, and present embodiment is 50% to introduce with preset value.During PCB layout, can adopt the order wire laying mode of alternate positive and negative, also other wire laying modes can be arranged, such as positive and negative negative positive mode.The PCI-E signal of this programme input can be multiple signals.Present embodiment is from the alternate positive and negative wire laying mode, and input two-way PCI-E signal is described.The processing of multiple signals only need increase corresponding correction circuit.

Original PCI-E signal gets into mode identificating circuit 601 and signal correcting circuit 602, and signal correcting circuit 602 is revised and exported according to the judged result of mode identificating circuit 601.Referring to Fig. 6, be the structural representation of a kind of PCI-E of enhancing data transmission stability of the present invention device embodiment.

Mode identificating circuit 601 simultaneously in former and later two positions of different time output, comes to the transmission mode that signal is judged in 4 outputs according to two paths of signals.Two signals are respectively a and b among the figure, and former and later two adjacent positions are respectively a ₀With a _l, b ₀With b ₁, according to:

a ₀With a ₁Not homophase, and b ₀With b ₁Not homophase, and a _lWith b ₁Different phase times are strange mould mode signal;

a ₀With a ₁Not homophase, and b ₀With b ₁Same phase time, for A road signal switches, B road signal remains unchanged;

a ₀With a ₁Homophase, and b ₀With b ₁Different phase times, for A road signal remains unchanged, B road signal switches;

a ₀With a ₁Homophase, and b ₀With b ₁Same phase time, two paths of signals all do not switch.

Make following logical formula:

Idol mould mode signal:

Even?Mode=(a ₀?XOR?a ₁)AND(b ₀?XOR?b ₁)AND(a _l?XNOR?b ₁)

Strange mould mode signal:

Odd?Mode=(a ₀?XOR?a ₁)AND(b ₀?XOR?b ₁)AND(a _l?XOR?b ₁)

A road signal switches, and B road signal remains unchanged:

A?Switch?&?B?Constant=(a ₀XOR?a ₁)AND(b ₀XNOR?b ₁)

A road signal remains unchanged, and B road signal switches:

A?Constant?＆?B?Switch=(a ₀?XNOR?a ₁)AND(b ₀?XOR?b ₁)

Two paths of signals all remains unchanged:

Both?Constant=(a ₀?XOR?a ₁)XNOR(b ₀?XOR?b ₁)

At any one time, more than to have only the differentiation result of a state in these five logical formulas be 1, other state is 0, has then judged each pattern respectively, and judged result is passed to signal correcting circuit.

Signal correcting circuit 602 is used for the judged result according to mode identificating circuit 601, when input signal is strange mould mode signal or multiple signals all during the signal of not saltus step, directly exports the PCI-E signal; When being even mould mode signal, with 50% edge of even mould mode signal as moment datum mark, according to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, the even mould mode signal of output advance/retard time; If overlay model signal; Isolate even mould mode signal and Qi Mo mode signal; With 50% edge of even mould mode signal as moment datum mark; According to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, signal and output that the even mould mode signal of advance/retard time is synthetic new with strange mould mode signal.

Signal correcting circuit 602 comprises parity mode mode signal split circuit; Referring to Fig. 4; Be parity mode mode signal split circuit structural representation of the present invention, the primary signal Uc (t) of primary signal Us of switching state (t) and maintenance steady state constitutes the PCI-E signal as a pair of driving source of circuit.When even mould mode signal during, at node A, B place, because of the electromotive force at this two place equates do not have electric current to flow through R as driving source _MSo the primary circuit mid portion is equivalent to open circuit; Work as resistance R _sMuch smaller than load R _LoadThe time, the voltage that node A (or B) locates just equals even mould mode signal.When strange mould mode signal during as driving source, because of electromotive force is opposite, resistance R _MThe centre be equivalent to ground connection; Work as R _MTo such an extent as to very little when being equivalent to zero, be equivalent to short circuit between node A, B place and the ground, promptly strange mould mode signal is equivalent to direct short-circuit to ground.For with Us (t) and Uc (t) during as a pair of driving source of circuit, the signal that node A (or B) locates just has only even mould mode signal Ue (t) so, according to following two formulas,

U _S(t)＝U _e(t)+U ₀(t)

U _c(t)＝U _e(t)-U ₀(t)

Also just obtained strange mould mode signal Uo (t), so the parity mode mode signal is all separated from primary signal.Wherein, R _S<<r _Load, R _M<<r _LoadConcrete delay time, synthetic method are identical with the method for above-mentioned enhancing PCI-E data transmission stability, repeat no more at this.

The above embodiment has only expressed several kinds of execution modes of the present invention, and it describes comparatively concrete and detailed, but can not therefore be interpreted as the restriction to claim of the present invention.Should be pointed out that for the person of ordinary skill of the art under the prerequisite that does not break away from the present invention's design, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection range of patent of the present invention should be as the criterion with accompanying claims.

Claims (10)

1. a method that strengthens the PCI-E data transmission stability is characterized in that, comprises step:

Obtain the PCI-E signal, judge the transmission mode of signal according to the PCI-E signal that obtains;

If even mould mode signal, with the preset edge of even mould mode signal as moment datum mark, according to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, the even mould mode signal of output advance/retard time;

If overlay model signal; Isolate even mould mode signal and Qi Mo mode signal; With the preset edge of even mould mode signal as moment datum mark; According to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, signal and output that the even mould mode signal of advance/retard time is synthetic new with strange mould mode signal.

2. the method for enhancing according to claim 1 PCI-E data transmission stability is characterized in that, also comprises step, if during the signal that strange mould mode signal or multiple signals all do not switch, then directly exports the PCI-E signal.

3. the method for enhancing PCI-E data transmission stability according to claim 1 and 2 is characterized in that the preset edge of said even mould mode signal is 50% edge.

4. the method for enhancing PCI-E data transmission stability according to claim 1 and 2 is characterized in that the step of said computing relay time △ D comprises:

$D_{\mathrm{odd}}=l\sqrt{(L_0-L_m)(C_0+C_m)}$

$D_{\mathrm{even}}=l\sqrt{(L_0+L_m)(C_0-C_m)}$

△D＝D _even-D _odd

Wherein, L ₀And L _mRepresent self-induction value and mutual inductance value respectively, C _oAnd C _mRepresent self-capacitance and mutual capacitance respectively, l representes conductor length, D _0ddAnd D _EvenRepresent the propagation delay of strange mould mode signal and the propagation delay of even mould mode signal respectively.

5. the method for enhancing PCI-E data transmission stability according to claim 1 and 2 is characterized in that, said overlay model signal, and the response of step of isolating even mould mode signal and Qi Mo mode signal comprises:

U _S(t)＝U _e(t)+U ₀(t)

U _c(t)＝U _e(t)-U ₀(t)

Wherein, Us (t) and Uc (t) represent the primary signal and the primary signal that keeps steady state of switching state respectively, and Us (t) and Uc (t) constitute the PCI-E signal, and Ue (t) representes even mould mode signal, and Uo (t) representes strange mould mode signal;

The synthetic new signal of idol mould mode signal and Qi Mo mode signal, step comprises:

U _S(t)＝U _e(t+△D)+U ₀(t)

U _c(t)＝U _e(t+△D)-U ₀(t)

Wherein, U ' _s(t) represent revised switching signal, U ' _c(t) represent revised inhibit signal, △ D representes time of delay.

6. a device that strengthens the PCI-E data transmission stability is characterized in that, comprising:

Mode identificating circuit is used to judge the transmission mode of the PCI-E signal of entering, selects the output signal of signal correcting circuit according to the transmission mode control MUX of signal;

Signal correcting circuit; To PCI-E Signal Separation Cheng Qimo mode signal and the even mould mode signal that gets into; With the preset edge of even mould mode signal as moment datum mark; According to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, the even mould mode signal of advance/retard time and the synthetic new signal of strange mould mode signal;

With said mode identificating circuit and the MUX that said signal correcting circuit is connected, be used for judged result according to said mode identificating circuit, when be strange mould mode signal or multiple signals all do not switch signal the time, select original PCI-E signal and output; When being even mould mode signal or overlay model signal, select new signal output.

7. the device of enhancing PCI-E data transmission stability according to claim 6 is characterized in that the preset edge of said even mould mode signal is 50% edge.

8. according to the device of claim 6 or 7 described enhancing PCI-E data transmission stabilities, it is characterized in that said signal correcting circuit also comprises delays module in advance, be used for the signal that gets into is shifted to an earlier date the delay time of one-period.

9. the device of enhancing PCI-E data transmission stability according to claim 8 is characterized in that, said mode identificating circuit judges that the standard of transmission mode comprises:

a ₀With a ₁Not homophase, and b ₀With b ₁Not homophase, and a ₁With b ₁Same phase time is even mould mode signal;

a ₀With a ₁Not homophase, and b ₀With b ₁Not homophase, and a ₁With b ₁Different phase times are strange mould mode signal;

a ₀With a ₁Not homophase, and b ₀With b ₁Same phase time, for A road signal switches, B road signal remains unchanged;

a ₀With a ₁Homophase, and b ₀With b ₁Different phase times, for A road signal remains unchanged, B road signal switches;

a ₀With a ₁Homophase, and b ₀With b ₁Same phase time, two paths of signals all do not switch.

Wherein, a ₀Represent original a-signal, b ₀Represent original B signal, a ₁Expression gets into the a-signal after Postponement module postpones, b ₁Expression gets into the B signal after Postponement module postpones.

10. a device that strengthens the PCI-E data transmission stability is characterized in that, comprising:

Mode identificating circuit is used to judge the transmission mode of the PCI-E signal of entering, according to the transmission mode control signal correction circuit output signal of signal;

Signal correcting circuit is used for the judged result according to mode identificating circuit, when input signal is strange mould mode signal or multiple signals all during the signal of not saltus step, directly exports the PCI-E signal; When being even mould mode signal, with the preset edge of even mould mode signal as moment datum mark, according to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, the even mould mode signal of output advance/retard time; If overlay model signal; Isolate even mould mode signal and Qi Mo mode signal; With the preset edge of even mould mode signal as moment datum mark; According to the datum mark computing relay time in the moment, with the even mould mode signal advance/retard time, signal and output that the even mould mode signal of advance/retard time is synthetic new with strange mould mode signal.

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