DEVICE FOR GENERATING TRANSMISSION CLOCK OF SINK AND TRANSMISSION METHOD USING GENERATED TRANSMISSION CLOCK

• US 20160308668A1
• Filed: 08/26/2014
• Published: 10/20/2016
• Est. Priority Date: 10/18/2013
• Status: Active Grant

• Current Assignee: Doestek
• Original Assignee: Doestek
• Inventors: Shin, Dae Jung, Kim, Tae Jin
• Granted Patent: US 10,164,767 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 1/04 Generating or distributing clock signals or signals derived directly therefrom
• CPC Class Codes: H04B 1/40 Circuits
• CPC Class Codes: H04L 7/0087 Preprocessing of received signal for synchronisation, e.g. by code conversion, pulse generation or edge detection
• CPC Class Codes: H04L 7/02 Speed or phase control by the received code signals, the signals containing no special synchronisation information H04L7/0075 takes precedence
• CPC Class Codes: H04L 7/033 using the transitions of the received signal to control the phase of the synchronising-signal-generating means, e.g. using a phase-locked loop
• CPC Class Codes: H04L 7/04 Speed or phase control by synchronisation signals H04L7/0075 takes precedence
• CPC Class Codes: H04L 7/041 using special codes as synchronising signal

Abstract

The present invention relates to a semiconductor device, more specifically to a device for generating a transmission clock in a sink without a reference clock and a method of transmitting data from the sink to a source by use of the generated transmission clock. The sink in accordance with an aspect of the present invention transmits return data by generating the transmission clock without a reference clock. The sink may include: a receiver configured to generate a digital control oscillator code by using a phase difference between a reception clock of a data signal received from a source and a recovered clock and configured to recover data from the data signal by using the recovered clock recovered by the generated digital control oscillator code; and a transmitter configured to generate a transmission clock by the digital control oscillator code having the recovered clock locked to the reception clock and configured to transmit return data to the source by using the transmission clock when a return data request identifier is received from the source.

Claims

1. A sink configured to transmit data by generating a transmission clock without a reference clock, comprising:

a receiver configured to generate a digital control oscillator code by using a phase difference between a reception clock of a data signal received from a source and a recovered clock and configured to recover data from the data signal by using the recovered clock recovered by the generated digital control oscillator code; and

a transmitter configured to generate a transmission clock by the digital control oscillator code having the recovered clock locked to the reception clock and configured to transmit return data to the source by using the transmission clock when a return data request identifier is received from the source.

2. The sink according to claim 1, wherein the receiver comprises:

a digital phase detector configured to detect the phase difference between the reception clock of the data signal received from the source and the recovered clock;

a time-to-digital converter configured to generate the digital control oscillator code by using the phase difference detected by the digital phase detector; and

a first digital control oscillator configured to output the recovered clock by using the digital control oscillator code.

3. The sink according to claim 1, wherein the receiver comprises:

a linear phase detector configured to detect the phase difference between the reception clock of the data signal received from the source and the recovered clock;

a charge pump configured to convert the phase difference detected by the linear phase detector into a control voltage;

an analog-to-digital converter configured to convert the control voltage into the digital control oscillator code; and

a first digital control oscillator configured to output the recovered clock by using the digital control oscillator code.

4. The sink according to claim 2, wherein the transmitter comprises:

a second digital control oscillator configured to output the transmission clock by using the digital control oscillator code; and

a serializer configured to serialize the return data by using the transmission clock.

5. The sink according to claim 2, further comprising a lock detector configured to compare the reception clock with the recovered clock and output a locking detection signal indicating whether the first digital control oscillator is locked.

6. The sink according to claim 1, wherein the return data comprises a header and option data.

7. The sink according to claim 6, wherein the return data further comprises a mini training pattern.

8. The sink according to claim 1, wherein the return data is a no return data identifier.

9. The sink according to claim 1, wherein the data signal received from the source and the return data are transmitted through a same channel.

18. The sink according to claim 3, wherein the transmitter comprises:

a second digital control oscillator configured to output the transmission clock by using the digital control oscillator code; and

a serializer configured to serialize the return data by using the transmission clock.

19. The sink according to claim 3, further comprising a lock detector configured to compare the reception clock with the recovered clock and output a locking detection signal indicating whether the first digital control oscillator is locked.

10. A method of transmitting data between a source and a sink, the source transmitting data by using a reference clock, the sink transmitting data by generating a transmission clock without a reference clock, the method comprising:

outputting the transmission clock by using a reception clock of a data signal received from the source, the transmission clock being outputted by a digital control oscillator included in a transmitter of the sink; and

changing a direction of data transmission between the source and the sink and transmitting return data to the source by using the transmission clock, when a return data request identifier is received from the source.

11. The method according to claim 10, wherein the outputting of the transmission clock by using the reception clock of the data signal received from the source comprises:

generating a digital control oscillator code by using a phase difference between the reception clock of the data signal received from the source and a recovered clock;

outputting the recovered clock by using the digital control oscillator code, the recovered clock being outputted by a digital control oscillator included in a receiver of the sink;

comparing the reception clock with the recovered clock and determining whether the digital control oscillator included in the receiver of the sink is locked; and

providing the digital control oscillator code to the digital control oscillator included in the transmitter of the sink when the digital control oscillator included in the receiver of the sink is locked.

13. The method according to claim 10, wherein the return data comprises a header and option data.

14. The method according to claim 10, wherein the return data is a no return data identifier.

15. The method according to claim 10, wherein the return data request identifier comprises a transmission completion identifier.

16. The method according to claim 10, wherein the return data has a variable size.

17. The method according to claim 10, further comprising, after the changing of the direction of data transmission between the source and the sink and transmitting the return data to the source by using the transmission clock when a return data request identifier is received from the source, transmitting a transmission completion identifier to the source when the transmission of the return is completed.

12. The method according to claim 12, wherein a blank section is started by a source end transmitted by the source.