Methods and transmitters for loop-back adaptive pre-emphasis data transmission

1. An adaptive pre-emphasis apparatus comprising:

a pre-emphasis circuit configured to pre-emphasize a serial data stream based on a pre-emphasis control value to transmit the pre-emphasized serial data stream to a receiver via a first transmission line;

a pre-emphasis controller configured to receive measured values of transmission errors of the pre-emphasized serial data stream from the receiver via a second transmission line, and configured to set the pre-emphasis control value corresponding to a minimum measured value of the transmission errors, to an optimum pre-emphasis control value;

wherein the pre-emphasis circuit comprises an output driver configured to receive serialized first input data and second input data that are inverted data of the serialized first input data, and configured to differentially amplify the first and the second input data; and

wherein the pre-emphasis circuit further comprises a pre-emphasis driver configured to receive third input data that are delayed data of the first input data by a predetermined time period and fourth input data that are inverted data of the third input data, and configured to pre-emphasize the third and the fourth input data based on a pre-emphasis strength value to output the pre-emphasized third and fourth input data.

2. The adaptive pre-emphasis apparatus of claim 1 , wherein the pre-emphasis controller maps the received measured values of the transmission errors to a corresponding pre-emphasis control value.

3. The adaptive pre-emphasis apparatus of claim 2 , wherein the pre-emphasis controller decodes the measured values of the transmission errors allocated to the corresponding pre-emphasis control value, and store the decoded measured values of the transmission errors in a memory device.

4. The adaptive pre-emphasis apparatus of claim 1 , wherein the pre-emphasis control value includes the pre-emphasis strength value.

5. The adaptive pre-emphasis apparatus of claim 4 , wherein the pre-emphasis strength value includes a binary bit value.

6. The adaptive pre-emphasis apparatus of claim 5 , wherein the pre-emphasis circuit pre-emphasizes the serial data stream based on the binary bit value of the pre-emphasis strength value to transmit the pre-emphasized serial data stream to the receiver via the first transmission line.

7. The adaptive pre-emphasis apparatus of claim 1 , wherein the transmission error includes the number of bit errors.

8. The adaptive pre-emphasis apparatus of claim 1 , wherein the transmission error includes an eye size.

9. The adaptive pre-emphasis apparatus of claim 8 , wherein the pre-emphasis controller sets the pre-emphasis control value corresponding to a maximum eye size, to an optimum pre-emphasis control value.

10. The adaptive pre-emphasis apparatus of claim 8 , wherein the pre-emphasis controller decodes the eye size to allocate the decoded eye size to a corresponding pre-emphasis control value.

11. The adaptive pre-emphasis apparatus of claim 1 , wherein the transmission error includes a jitter value.

12. An adaptive pre-emphasis method comprising:

pre-emphasizing a first serial data stream based on a plurality of pre-emphasis control values to transmit the pre-emphasized serial data stream to a receiver via a first transmission line;

loop-backing the pre-emphasized serial data stream to a transmitter via a second transmission line;

measuring transmission errors of a second serial data stream loop-backed through the receiver via the second transmission line;

allocating the measured transmission error to each corresponding pre-emphasis control value; and

setting the pre-emphasis control value corresponding to a minimum transmission error, to an optimum pre-emphasis strength value, wherein pre-emphasizing the first serial data stream comprises:

receiving serialized first input data and second input data comprising inverted data of the serialized first input data, and differentially amplifying the first and the second input data; and

receiving third input data comprising delayed data of the first input data by a predetermined time period and fourth input data comprising inverted data of the third input data, and pre-emphasizing the third and the fourth input data based on a pre-emphasis strength value to output the pre-emphasized third and fourth input data.

13. The adaptive pre-emphasis method of claim 12 , further comprising pre-emphasizing the second serial data stream based on the optimum pre-emphasis strength value, to provide the pre-emphasized second serial data stream via the first transmission line.

14. The adaptive pre-emphasis method of claim 12 , wherein the pre-emphasis control value includes the pre-emphasis strength value.

15. The adaptive pre-emphasis method of claim 12 , wherein the pre-emphasis strength value includes a binary bit value.

16. The adaptive pre-emphasis method of claim 15 , wherein the step of pre-emphasizing pre-emphasizes the first serial data stream based on the binary bit value of the pre-emphasis strength value to transmit the pre-emphasized first serial data to the receiver via the first transmission line.

17. The adaptive pre-emphasis method of claim 12 , wherein the transmission error includes the number of bit errors.

18. The adaptive pre-emphasis method of claim 12 , wherein the transmission error includes an eye size.

19. The adaptive pre-emphasis method of claim 18 , wherein the pre-emphasis control value corresponding to the eye size having a maximum value is set to an optimum pre-emphasis control value.

20. The adaptive pre-emphasis method of claim 12 , wherein the transmission error includes a jitter value.