Adaptive signal termination
An input signal is transmitted from a first device to a second device. At the second device the input signal method is received, and an output signal is generated in response to the input signal. The output signal is sensed, and the input signal is dynamically terminated in response to sensing the output data. In some embodiments, the receiving, generating and dynamically terminating occur within a single integrated circuit. In some embodiments, the method includes detecting a signal voltage level of the input signal and causing a termination voltage level to change from a first voltage level to a second voltage level in response to the signal voltage level.
1. A method comprising:
receiving an input signal from a transmission line;
generating an output data in response to the input signal; and
dynamically terminating the transmission line in response to the input signal, including:
detecting a signal voltage level of the input signal; and
changing a termination voltage level from a first voltage level to a second voltage level based on the detected signal voltage level, wherein the first and second voltage levels differ from ground.
2. The method according to claim 1 wherein the receiving, generating and dynamically terminating occur within a single integrated circuit.
3. The method according to claim 1 further comprising selecting a selected reference voltage from among a plurality of reference voltages based on the output data.
4. The method according to claim 1 wherein dynamically terminating further comprises sensing a current associated with the input signal.
5. A method comprising:
receiving an input signal from a transmission line;
generating an output data in response to the input signal;
sensing the output data; and
dynamically terminating the transmission line in response to sensing the output data, including:
detecting a signal voltage level of the output signal; and
changing a termination voltage level from a first voltage level to a second voltage level based on the detected signal voltage level, wherein the first and second voltage levels differ from ground.
6. The method according to claim 5 , wherein dynamically terminating comprises selecting between a plurality of termination circuits.
7. The method according to claim 6 , wherein one of the plurality of termination circuits drives the input signal high.
8. The method according to claim 6 , wherein one of the plurality of termination circuits drives the input signal low.
9. The method according to claim 6 , wherein one of the plurality of termination circuits drives the input signal to a predetermined voltage.
10. The method according to claim 6 , wherein selecting between the plurality of termination circuits occurs through a switch.
11. The method according to claim 6 , wherein selecting between the plurality of termination circuits occurs through a transistor.
12. The method according to claim 5 , further comprising selecting a selected reference voltage from among a plurality of reference voltages based on the output data.
13. The method according to claim 12 , wherein generating the output data depends on the selected reference voltage, and the method includes detecting a cross-over between the input signal and the selected reference voltage.
14. The method according to claim 5 , including transmitting the input signal from a first device to a second device and receiving the input signal at the second device, wherein the first device is a memory device.
15. The method according to claim 5 , including transmitting the input signal from a first device to a second device and receiving the input signal at the second device, wherein the first device is a memory controller.