Serial transmission device, method, and computer readable medium storing program

1. A serial transmission device comprising:

a transmitting unit that transmits data;

a receiving unit that receives the data; and

a plurality of serial transmission paths that connect the transmitting unit with the receiving unit, and are used to transmit the data from the transmitting unit to the receiving unit, wherein

the receiving unit includes an inter-lane skew information generation unit that generates inter-lane skew information about skew of each of the serial transmission paths in the receiving unit, and transmits the generated inter-lane skew information to the transmitting unit,

the transmitting unit includes a data conversion rule generation unit that generates a conversion rule used to determine distribution of the data to each of the serial transmission paths based on the inter-lane skew information in the transmitting unit, wherein

the receiving unit measures arrival times of commands each transmitted through a respective one of the plurality of serial transmission paths,

the inter-lane skew information generation unit generates differences each between an earliest arrival time among the measured arrival times of the serial transmission paths and each of the arrival times of the serial transmission paths as the inter-lane skew information,

the receiving unit transmits the generated inter-lane skew information, and

the data conversion rule generation unit generates the conversion rule based on the inter-lane skew information so that a larger amount of data is transmitted through a serial transmission path capable of transmitting data more quickly among the serial transmission paths, wherein the transmitting unit comprises:

the data conversion rule generation unit;

a parallel-serial conversion circuit that converts parallel data into serial data; and

a data conversion unit that distributes serial data converted by the parallel-serial conversion circuit to each of the serial transmission paths in accordance with the conversion rule, and

the receiving unit comprises:

the inter-lane skew information generation unit;

a deskew circuit that performs waiting for each serial data input through each of the serial transmission paths;

a data decode unit that performs decode processing on serial data obtained through the deskew circuit based on the conversion rule; and

a serial-parallel conversion circuit that converts the serial data into parallel data.

2. The serial transmission device according to claim 1 , wherein the inter-lane skew information is transmitted through the serial transmission path.

3. The serial transmission device according to claim 2 , wherein the inter-lane skew information is transmitted as link training information.

4. The serial transmission device according to claim 1 , wherein the conversion rule is transmitted through the serial transmission path.

5. A serial transmission method comprising:

measuring arrival times of commands at a reception side, each of the commands being transmitted from a transmission side through a respective one of a plurality of serial transmission paths;

generating inter-lane skew information for each of the serial transmission paths at the reception side, the inter-lane skew information being a difference between an earliest arrival time among the measured arrival times of the serial transmission paths and a respective one of the arrival times of the serial transmission paths;

transmitting the generated inter-lane skew information of the plurality of serial transmission paths from the reception side to the transmission side; and

determining distribution of data to each of the serial transmission paths based on the transmitted inter-lane skew information on the transmission side so that a larger amount of data is transmitted through a serial transmission path capable of transmitting data more quickly among the serial transmission paths, wherein the method further comprises:

converting parallel data into serial data;

distributing the serial data to each of the serial transmission paths in accordance with a conversion rule;

performing waiting for each serial data input through each of the serial transmission paths;

performing decode processing on serial data based on the conversion rule; and

converting the serial data into parallel data.

6. The serial transmission method according to claim 5 , further comprising:

transmitting a conversion rule used to determine distribution of the data from the transmission side to the reception side; and

restoring received data to an original state before the distribution based on the conversion rule on the reception side.

7. The serial transmission method according to claim 5 , wherein the inter-lane skew information is transmitted as link training information.

8. The serial transmission method according to claim 5 , further comprising:

converting parallel data into serial data on the reception side; and

converting serial data into parallel data on the transmission side.

9. A non-transitory computer readable medium storing a serial transmission program used to control an apparatus that transmits data from a transmitting unit to a receiving unit through a plurality of serial transmission paths, wherein the program causes the apparatus to:

measure arrival times of commands at a reception side, each of the commands being transmitted from a transmission side through a respective one of a plurality of serial transmission paths;

generate inter-lane skew information for each of the serial transmission paths at the reception side, the inter-lane skew information being a difference between an earliest arrival time among the measured arrival times of the serial transmission paths and a respective one of the arrival times of the serial transmission paths;

transmit the generated inter-lane skew information of the plurality of serial transmission paths from the reception side to the transmission unit; and

determines distribution of data to each of the serial transmission paths based on the transmitted inter-lane skew information in the transmitting unit so that a larger amount of data is transmitted through a serial transmission path capable of transmitting data more quickly among the serial transmission paths, wherein the program further causes the apparatus to:

convert parallel data into serial data;

distribute the serial data to each of the serial transmission paths in accordance with a conversion rule;

perform waiting for each serial data input through each of the serial transmission paths;

perform decode processing on serial data based on the conversion rule; and

convert the serial data into parallel data.

10. The serial transmission device according to claim 1 , wherein the transmitting unit optimizes a data frame format based on the inter-lane skew information transmitted from the receiving unit.

11. The serial transmission device according to claim 1 , wherein the transmitting unit distributes the data to each of the serial transmission paths in such a manner that an amount of data transmitted within a fixed time period decreases with increase of skew of the serial transmission paths.

12. The serial transmission method according to claim 5 , wherein a data frame format is optimized on the transmission side based on the inter-lane skew information transmitted from the reception side.

13. The serial transmission method according to claim 5 , wherein the data is distributed to each of the serial transmission paths on the transmission side in such a manner that an amount of data transmitted within a fixed time period decreases with increase of skew of the serial transmission paths.