Semiconductor memory device and semiconductor memory system for compensating crosstalk
A semiconductor memory device and a semiconductor memory system. The semiconductor memory device includes channels configured to transmit signals from a transmitter to a receiver, and a crosstalk compensator. The crosstalk compensator may be connected between the channels to compensate for crosstalk. The crosstalk compensator may comprise a capacitor connected in parallel between the channels, and a switching unit connected between the capacitor and one of the channels. The switching unit may control connections or disconnections between the capacitor and the channel. Therefore, the semiconductor memory device and the semiconductor memory system compensate for crosstalk occurring between transmitted signals that are out of phase with each other.
1. A semiconductor memory device comprising:
a plurality of channels configured to transmit signals from a transmitter to a receiver;
a crosstalk compensator connected between the channels to compensate for crosstalk, wherein the crosstalk compensator comprises:
at least one capacitor connected in parallel between the channels; and
at least one switching unit connected between the at least one capacitor and one of the channels, the at least one switching unit being configured to control connections or disconnections between the at least one capacitor and the channel; and
a controller configured to control the at least one switching unit to determine capacitance of the crosstalk compensator,
wherein the controller is configured to transmit test signals through the channels and turn on or off the at least one switching unit to minimize crosstalk occurring between the transmitted test signals.
2. The semiconductor memory device of claim 1 , wherein the crosstalk compensator is connected between the channels in substantially a center region between the transmitter and the receiver.
3. The semiconductor memory device of claim 1 , wherein the crosstalk compensator is connected between the channels and adjacent to the transmitter.
4. The semiconductor memory device of claim 1 , wherein the crosstalk compensator is connected between the channels and adjacent to the receiver.
5. The semiconductor memory device of claim 1 , wherein the at least one capacitor comprises at least one first capacitor and the at least one switching unit comprises at least one first switching unit, wherein the crosstalk compensator comprises at least one second capacitor and at least one second switching unit connected between the channels and adjacent to the transmitter, and wherein the at least one first capacitor and the at least one first switching unit are connected between the channels and adjacent to the receiver.
6. The semiconductor memory device of claim 1 , wherein the crosstalk compensator is connected between adjacent channels.
7. The semiconductor memory device of claim 1 , wherein the crosstalk compensator is connected between channels that are not adjacent to each other.
8. The semiconductor memory device of claim 1 , wherein the controller is configured to control the at least one switching unit responsive to delay degrees of the transmitted test signals to determine the capacitance.
9. The semiconductor memory device of claim 1 , wherein the controller is configured to control the at least one switching unit responsive to one of a signal applied from an external source and a Mode Register Set (MRS) signal to determine the capacitance.
10. The semiconductor memory device of claim 1 , wherein the at least one switching unit is a switch that is turned on or off responsive to a signal output from the controller.
11. The semiconductor memory device of claim 10 , wherein the signal output from the controller is generated by comparing input signals of the transmitter with output signals of the receiver.
12. The semiconductor memory device of claim 1 , wherein the at least one switching unit is a transistor that comprises a gate, a first node, and a second node, wherein a signal output from the controller is applied to the gate, wherein the first node is connected to the channel, and wherein the second node is connected to the capacitor.
13. A semiconductor memory system comprising:
a plurality of channels configured to transmit signals from a first memory chip to a second memory chip;
a crosstalk compensator connected between the channels to compensate for crosstalk, wherein the crosstalk compensator comprises:
at least one capacitor connected in parallel between the channels; and
at least one switching unit connected between the capacitors and one of the channels, and the at least one switching unit is configured to control connections or disconnections between the at least one capacitor and the channel; and
a controller configured to control the at least one switching unit to determine capacitance of the crosstalk compensator, wherein the controller is configured to transmit test signals through the channels and to turn on or off the at least one switching unit to minimize crosstalk occurring between the transmitted test signals.
14. The semiconductor memory system of claim 13 , wherein the crosstalk compensator is connected between the channels in substantially a center region between the first and second memory chips.
15. The semiconductor memory system of claim 13 , wherein the crosstalk compensator is connected between the channels and adjacent to the first memory chip.
16. The semiconductor memory system of claim 13 , wherein the crosstalk compensator is connected between the channels and adjacent to the second memory chip.
17. The semiconductor memory system of claim 13 , wherein the at least one capacitor comprises at least one first capacitor and the at least one switching unit comprises at least one first switching unit, wherein the crosstalk compensator comprises at least one second capacitor and at least one second switching unit connected between the channels and adjacent to the first memory chip, and wherein the at least one first capacitor and the at least one first switching unit are connected between the channels and adjacent to the second memory chip.
18. The semiconductor memory device of claim 13 , wherein the controller is configured to control the at least one switching unit responsive to one of a signal applied from an external source and a Mode Register Set (MRS) signal to determine the capacitance.
19. The semiconductor memory device of claim 13 , wherein the controller is configured to generate a signal to control the at least one switching unit responsive to comparing input signals of the transmitter with output signals of the receiver.
20. A semiconductor memory device comprising:
first through fifth sequentially adjacent channels configured to transmit signals from a transmitter to a receiver; and
a crosstalk compensator connected between the channels to compensate for crosstalk,
wherein the crosstalk compensator comprises:
a first capacitor and a second capacitor connected in parallel between the first channel and the third channel;
a third capacitor and a fourth capacitor connected in parallel between the third channel and the fifth channel;
a first switching unit and a second switching unit connected between the first capacitor and the second capacitor, respectively, and the first channel, wherein the first and second switching units are configured to control connections or disconnections between the first and second capacitors, respectively, and the first channel; and
a third switching unit and a fourth switching unit connected between the third capacitor and the fourth capacitor, respectively, and the third channel, wherein the third and fourth switching units are configured to control connections or disconnections between the third and fourth capacitors, respectively, and the third channel.
21. A semiconductor memory device comprising:
a plurality of channels configured to transmit signals from a transmitter to a receiver;
a crosstalk compensator connected between the channels to compensate for crosstalk, wherein the crosstalk compensator comprises:
at least one capacitor connected in parallel between the channels; and
at least one switching unit connected between the at least one capacitor and one of the channels, the at least one switching unit being configured to control connections or disconnections between the at least one capacitor and the channel; and
a controller configured to control the at least one switching unit to determine capacitance of the crosstalk compensator,
wherein the controller is configured to transmit test signals through the channels and to control the at least one switching unit responsive to delay degrees of the transmitted test signals to determine the capacitance.
22. A semiconductor memory device comprising:
a plurality of channels configured to transmit signals from a transmitter to a receiver;
a crosstalk compensator connected between the channels to compensate for crosstalk, wherein the crosstalk compensator comprises:
at least one capacitor connected in parallel between the channels; and
at least one switching unit connected between the at least one capacitor and one of the channels, the at least one switching unit being configured to control connections or disconnections between the at least one capacitor and the channel; and
a controller configured to control the at least one switching unit to determine capacitance of the crosstalk compensator,
wherein the controller is configured to control the at least one switching unit responsive to one of a signal applied from an external source and a Mode Register Set (MRS) signal to determine the capacitance.