This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2018-0036138, filed on Mar. 28, 2018, which is incorporated herein by reference in its entirety.
The present invention relates to an improved integrated circuit and a method of operating the same.
A multi-channel parallel interface is frequently used because it allows high-speed communication. However, inductive and capacitive coupling between adjacent channels may cause far-end crosstalk (FEXT).
Since the noise caused by the crosstalk between the adjacent lines disturbs high-speed communication, there is a demand for a technique capable of removing crosstalk.
Various embodiments are directed to a technology capable of effectively removing crosstalk between adjacent transmission lines.
In an embodiment, an integrated circuit may include: a first transmission line; a second transmission line; a first compensator circuit suitable for generating a first compensation signal by delaying and differentiating a signal transferred through the second transmission line; a second compensator circuit suitable for generating a second compensation signal by delaying and differentiating a signal transferred through the first transmission line; a first receiver circuit suitable for receiving the signal transferred through the first transmission line, and compensating for the signal transferred through the first transmission line using the first compensation signal; and a second receiver circuit suitable for receiving the signal transferred through the second transmission line, and compensating for the signal transferred through the second transmission line using the second compensation signal.
The first compensator circuit may have a delay value which corresponds to ([delay value of far-end crosstalk from the second transmission line to the first transmission line]−[delay value of the first transmission line]), and the second compensator circuit may have a delay value which corresponds to ([delay value of far-end crosstalk from the first transmission line to the second transmission line]−[delay value of the second transmission line]).
In an embodiment, a method for operating an integrated circuit may include: generating a first compensation signal by delaying and differentiating a signal transferred through a second transmission line; generating a second compensation signal by delaying and differentiating a signal transferred through a first transmission line; receiving the signal transferred through the first transmission line, and compensating for the signal transferred through the first transmission line using the first compensation signal; and receiving the signal transferred through the second transmission line, and compensating for the signal transferred through the second transmission line using the second compensation signal.
Various embodiments will be described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and thus is not limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure is thorough and complete and fully conveys the scope of the present invention to those skilled in the art. Throughout the disclosure, like reference numerals refer to like parts throughout the various figures and embodiments of the present invention. Also, throughout the specification, reference to “an embodiment,” “another embodiment,” or the like is not necessarily to only one embodiment, and different references to any such phrase are not necessarily to the same embodiment(s).
Referring to
The first transmitter 311 may transmit a signal through the first transmission line 301, and the second transmitter 312 may transmit a signal through the second transmission line 302. In FIG. 3, ‘FEXT1’ represents far-end crosstalk which is caused at a receiving terminal of the second transmission line 302 by the signal transmitted through the first transmission line 301, and ‘FEXT2’ represents far-end crosstalk which is caused at a receiving terminal of the first transmission line 301 by the signal transmitted through the second transmission line 302. Furthermore, ‘THRU1’ indicates that the signal transmitted by the first transmitter 311 has passed through the first transmission line 301, and ‘THRU2’ indicates that the signal transmitted by the second transmitter 312 has passed through the second transmission line 302.
The first differentiator circuit 331 may generate a first compensation signal XTC1 by differentiating the signal THRU2 transmitted through the second transmission line 302. The second differentiator circuit 332 may generate a second compensation signal XTC2 by differentiating the signal THRU1 transmitted through the first transmission line 301.
The first receiver circuit 321 may receive the signal THRU1 of the first transmission line 301, and compensate for the signal THRU1 using the first compensation signal XTC1. The first receiver circuit 321 may add up the signal THRU1 and the first compensation signal XTC1, in order to cancel the crosstalk FEXT2 which occurred in the signal THRU1. ‘RCV1’ may represent the signal received by the first receiver circuit 321.
The second receiver circuit 322 may receive the signal THRU2 of the second transmission line 302, and compensate for the signal THRU2 using the second compensation signal XTC2. The second receiver circuit 322 may add up the signal THRU2 and the second compensation signal XTC2, in order to cancel the crosstalk FEXT1 which occurred in the signal THRU2. ‘RCV2’ may represent the signal received by the second receiver circuit 322.
For example,
Referring to
The second differentiator circuit 332 may generate the second compensation signal XTC2 by differentiating the signal THRU1. The second compensation signal XTC2 may have the opposite polarity to the far-end crosstalk FEXT1.
Since the second receiver circuit 322 receives the signal THRU2 and performs the process of adding up the signal THRU2 and the second compensation signal XTC2, the far-end crosstalk FEXT1 may be removed from the received signal RCV2.
The operation of
Referring to
The second differentiator circuit 332 may generate the second compensation signal XTC2 by differentiating the signal THRU1 of the first transmission line 301. A timing mismatch may be present between the second compensation signal XTC2 and the noise of the signal THRU2 of the second transmission line 302.
The second receiver circuit 322 may receive the signal THRU2 and perform a process of adding up the signal THRU2 and the second compensation signal XTC2. However, the far-end crosstalk FEXT1 may not be normally removed from the signal RCV2 received by the second receiver circuit 322, due to the timing mismatch between the second compensation signal XTC2 and the noise present in the signal THRU2.
Referring to
The first compensator circuit 610 may generate the first compensation signal XTC1 by delaying and differentiating the signal THRU2 of the second transmission line 302. The first compensator circuit 610 may be different from the first differentiator circuit 331 of
The first compensator circuit 610 may include a first delay circuit 611 and a first differentiator circuit 612. The first delay circuit 611 may have a delay value which approximately corresponds to ([delay value of far-end crosstalk FEXT2 from second transmission line 302 to first transmission line 301]−[delay value of first transmission line 301]−[delay value of first differentiator circuit 612]). For example,
The second compensator circuit 620 may generate the second compensation signal XTC2 by delaying and differentiating the signal THRU1 of the first transmission line 301. The second compensator circuit 620 may be different from the second differentiator circuit 332 of
The second compensator circuit 620 may include a second delay circuit 621 and a second differentiator circuit 622. The second delay circuit 621 may have a delay value which approximately corresponds to ([delay value of far-end crosstalk FEXT1 from first transmission line 301 to second transmission line 302]−[delay value of second transmission line 302]-[delay value of second differentiator circuit 622]). For example,
Since the first and second transmission lines 301 and 302 have the same length and characteristics, the delay value of the first compensator circuit 610 may be equal to the delay value of the second compensator circuit 620.
Now, the delay value, which the first and second compensator circuits 610 and 620 have, will be described.
Assuming that a transfer function of the first and second transmission lines 301 and 302 is a low pass filter, the transfer function of the channels 301 and 302 may be expressed as Equation 1 below.
Since the crosstalks FEXT1 and FEXT2 can be represented as differentiated values of the signals transmitted to the transmission lines 301 and 302, a transfer function of the crosstalks FEXT1 and FEXT2 may be expressed as Equation 2 below.
In Equation 2, τ represents forward coupling strength which increases as the distance d between the lines (or channels) 301 and 302 is reduced.
Since the transfer functions of the lines 301 and 302 and the crosstalks FEXT1 and FEXT2 are known, the delay value of the lines 301 and 302 may be expressed as Equation 3, and the delay value of the crosstalks FEXT1 and FEXT2 may be expressed as Equation 4.
A difference Td between the delay value DFEXT(ω) of the crosstalks FEXT1 and FEXT2 and the delay value DCH(ω) of the transmission lines 301 and 302 may be expressed as Equation 5 below.
The difference Td of Equation 5 may correspond to a delay value which the first and second compensator circuits 610 and 620 need to have.
The first differentiator circuit 612 within the first compensator circuit 610 and the second differentiator circuit 622 within the second compensator circuit 620 also inevitably have delay values. Hereafter, the delay value of the first and second differentiator circuits 612 and 622 and the delay value of the first and second delay circuits 611 and 621 will be described.
Referring to
The first differentiator circuit 612 configured in the form of an RC high pass filter may have a delay value Ddiff which is expressed as Equation 6 below.
The delay value which the first and second compensator circuits 610 and 620 need to have is the difference Td of Equation 5. The delay value of the first and second differentiator circuits 612 and 622 is the delay value Ddiff of Equation 6. Therefore, the first and second delay circuits 611 and 612 need to have a delay value of (Td−Ddiff), and the delay value may be expressed as Equation 7 below.
The first and second delay circuits 611 and 612 may be designed to have the delay value of Equation 7. Alternatively, a variety of delays such as an RC delay and inverter delay may be applied as the delay method of the first and second delay circuits 611 and 612.
When the first and second differentiator circuits 612 and 622 are designed to have the same delay value as the delay value Td which the first and second compensator circuits 610 and 620 need to have, the first and second delay circuits 611 and 621 may be omitted from the first and second compensator circuits 610 and 620. For example, when the product of the capacitance CXTC and the resistance value RXTC of the first and second differentiator circuits 621 and 622 is equal to the forward coupling strength τ (RXTC*CXTC=τ), the first and second delay circuits 611 and 612 may be omitted because Equation 7 becomes zero.
Referring to
The first receiver 810 may receive the signal THRU1 transferred through the first transmission line 301 and drive the signal RCV1 in response to the signal THRU1.
The second receiver 820 may receive the first compensation signal XTC1 and drive the signal RCV1 in response to the first compensation signal XTC1.
Finally, the signal THRU1 and the first compensation signal XTC1 may be added up by the first and second receivers 810 and 820, thereby generating the signal RCV1. The first and second receivers 810 and 820 may have gains which are differentially adjusted depending on the strength of the crosstalk FEXT2.
For example,
The second compensator circuit 620 may generate the second compensation signal XTC2 by delaying and differentiating the signal THRU1 of the first transmission line 301. Thus, the timing of the second compensation signal XTC2 and the timing of the noise generated in the signal THRU2 may be matched with each other through the delay operation of the second compensator circuit 620.
Since the second receiver circuit 322 receives the signal THRU2 and performs the process of adding up the signal THRU2 of the second transmission line 302 and the second compensation signal XTC2, the far-end crosstalk FEXT1 may be removed from the received signal RCV2.
Comparing
In accordance with embodiments of the present invention, the integrated circuit may effectively remove crosstalk between adjacent lines.
Although various embodiments have been described and illustrated, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.
Number | Date | Country | Kind |
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10-2018-0036138 | Mar 2018 | KR | national |