Semiconductor integrated circuit, receiver device, and method for controlling semiconductor integrated circuit
According to one embodiment, there is provided a semiconductor integrated circuit including a first equalizer and a clock reproduction circuit. The first equalizer boosts a data signal. The clock reproduction circuit extracts from the boosted data signal information of a pair consisting of a rise edge and a fall edge which are temporarily separated from each other by N or more times (N is an integer of two or higher) as much as a clock cycle, performs a phase adjustment based on the information about the pair of the rise edge and the fall edge, and reproduces a clock.
1. A semiconductor integrated circuit comprising:
a first equalizer configured to boost a data signal; and
a clock reproduction circuit configured to extract from the boosted data signal information of a pair of a rise edge and a fall edge which are temporarily separated from each other by N or more times (N is an integer of two or higher) as much as a clock cycle, perform a first phase adjustment based on the information about the pair of the rise edge and the fall edge, and reproduce a clock.
2. The semiconductor integrated circuit according to claim 1 , wherein
the clock reproduction circuit includes
an extraction circuit configured to extract from the boosted data signal, the information of the pair of the rise edge and the fall edge,
a control circuit configured to determine a control amount for the first phase adjustment based on the information of the pair of the rise edge and the fall edge, and
a generation circuit configured to generate the clock based on the determined control amount.
3. The semiconductor integrated circuit according to claim 2 , wherein
the control circuit is configured to increase the control amount derived with use of the pair of the rise edge and the fall edge N times, and use the increased amount as the control amount for the first phase adjustment.
4. The semiconductor integrated circuit according to claim 2 , wherein
the generation circuit comprises
a charge pump circuit that includes a capacitance element and a variable current source configured to store charge the capacitance element based on a current amount corresponding to the control amount, and
a voltage controlled oscillator circuit configured to generate the clock based on voltage of the capacitance element, and
wherein the determined control amount is a control amount of current to flow in the charge pump circuit.
5. The semiconductor integrated circuit according to claim 2 , further comprising:
a detection circuit configured to detect information of edges from the boosted data signal; and
a holding circuit configured to store the detected information of the edge,
wherein the extraction circuit is configured to extract the information of the pair of the rise edge and the fall edge based on the stored information of the edges.
6. The semiconductor integrated circuit according to claim 5 , wherein
the holding circuit comprises
a first register configured to store a signal indicating a edge,
a second register configured to store a signal indicating a rise edge, and
a third register configured to store a signal indicating a fall edge.
7. The semiconductor integrated circuit according to claim 1 , further comprising:
a first adjustment circuit configured to adjust a boost amount of the first equalizer.
8. The semiconductor integrated circuit according to claim 7 , further comprising:
a sampler configured to determine a logical value of the boosted data signal in synchronization with the clock; and
an identification circuit configured to detect an identification pattern contained in the data signal based on a determination result of the sampler,
wherein the first adjustment circuit is configured to end the adjustment of the boost amount based on a detection of the identification pattern, and
wherein the clock reproduction circuit is configured to end the first phase adjustment based on the detection of the identification pattern, and start a second phase adjustment based on information of a plurality of edges extracted from the boosted data signal.
9. The semiconductor integrated circuit according to claim 8 , further comprising:
a second equalizer configured to correct the boosted data signal; and
a second adjustment circuit configured to start adjustment of a correction amount of the second equalizer based on the detection of the identification pattern, and end the adjustment of the correction amount of the second equalizer based on a next detection of the identification pattern.
10. The semiconductor integrated circuit according to claim 8 , further comprising:
a second equalizer configured to correct the boosted data signal; and
a second adjustment circuit configured to start adjustment of a correction amount of the second equalizer before the detection of the identification pattern, and end the adjustment of the correction amount of the second equalizer based on the detection of the identification pattern.
11. A receiver device comprising:
a semiconductor integrated circuit; and
a circuit configured to receive data output from the semiconductor integrated circuit,
wherein the semiconductor integrated circuit comprises
a first equalizer configured to boost a data signal; and
a clock reproduction circuit configured to extract from the boosted data signal information of a pair of a rise edge and a fall edge which are temporarily separated from each other by N or more times (N is an integer of two or higher) as much as a clock cycle, perform a first phase adjustment based on the information about the pair of the rise edge and the fall edge, and reproduce a clock.
12. The receiver device according to claim 11 , wherein
the clock reproduction circuit includes
an extraction circuit configured to extract from the boosted data signal the information of the pair of the rise edge and the fall edge,
a control circuit configured to determine a control amount for the first phase adjustment based on the information about the pair consisting of the rise edge and the fall edge, and
a generation circuit configured to generate the clock based on the determined control amount.
13. The receiver device according to claim 12 , wherein
the control circuit is configured to increase the control amount derived with use of the pair of the rise edge and the fall edge N times, and use the increased amount as the control amount for the first phase adjustment.
14. The receiver device according to claim 12 , wherein
the generation circuit comprises
a charge pump circuit configured to include a capacitance element and a variable current source configured to store charge the capacitance element based on a current amount corresponding to the control amount, and
a voltage controlled oscillator circuit configured to generate the clock based on voltage of the capacitance element, and
wherein the determined control amount is a control amount of current to flow in the charge pump circuit.
15. The receiver device according to claim 11 , wherein
the semiconductor integrated circuit further includes a first adjustment circuit configured to adjust a boost amount of the first equalizer.
16. The receiver device according to claim 15 , wherein
the semiconductor integrated circuit further includes
a sampler configured to determine a logical value of the boosted data signal in synchronization with the clock; and
an identification circuit configured to detect an identification pattern contained in the data signal based on a determination result of the sampler,
wherein the first adjustment circuit is configured to end the adjustment of the boost amount based on a detection of the identification pattern, and
wherein the clock reproduction circuit is configured to end the first phase adjustment based on the detection of the identification pattern, and start a second phase adjustment based on information of a plurality of edges extracted from the boosted data signal.
17. A method of controlling a semiconductor integrated circuit comprising:
adjusting a boost amount of a first equalizer configured to boost a data signal; and,
extracting from the data signal boosted by the first equalizer information of a pair of a rise edge and a fall edge which are temporarily separated from each other by N or more times (N is an integer of two or higher) as much as a clock cycle, performing a first phase adjustment based on the information about the pair of the rise edge and the fall edge, and reproducing a clock.
18. The method of controlling the semiconductor integrated circuit according to claim 17 , further comprising:
extracting from the boosted data signal the information of the pair of the rise edge and the fall edge,
determining a control amount for the first phase adjustment based on the information of the pair consisting of the rise edge and the fall edge, and
generating the clock based on the determined control amount.
19. The method of controlling the semiconductor integrated circuit according to claim 18 , wherein
the determining includes
increasing the control amount derived with use of the pair of the rise edge and the fall edge N times, and using the increased amount as the control amount for the first phase adjustment.
20. The method of controlling the semiconductor integrated circuit according to claim 17 , further comprising:
adjusting a boost amount of the first equalizer.