Method for enhancing data transmission efficiency

1. A method for a data transmission system having a host, a subsystem and a transmission interface, utilized for the host to transmit and receive a data from a memory of the subsystem via the transmission interface, the method comprising:

the host outputting a query command to the subsystem via the transmission interface for querying available memory utilization of the subsystem;

the subsystem outputting a return message to the host via the transmission interface for indicating the available memory utilization according to the query command; and

controlling data transmission from the host to the subsystem according to the return message;

wherein the step of controlling data transmission from the host to the subsystem according to the return message comprises adjusting a size of a data packet transmitted from the host to the subsystem according to the available memory utilization indicated by the return message,

wherein the step of the subsystem outputting the return message to the host via the transmission interface according to the query command comprises:

generating a sliding window;

adjusting a length of the sliding window for recording a storage value of the memory according to each received data and transmitted data; and

the subsystem outputting the return message to the host via the transmission interface according to the length of the sliding window.

2. The method of claim 1 , wherein the return message is carried in a packet.

3. The method of claim 1 , wherein a step of controlling data transmission from the host to the subsystem according to the return message further comprises stopping data transmission from the host to memory of the subsystem via the transmission interface when the return message indicates that the available memory utilization is below a default value.

4. The method of claim 1 , wherein the step of controlling data transmission from the host to the subsystem according to the return message further comprises controlling data transmission from the host to memory of the subsystem via the transmission interface when the return message indicates that the available memory utilization is above a default value.

5. The method of claim 1 , wherein a data processing rate of the subsystem is higher than a data transmission rate of the transmission interface.

6. A method for a data transmission system having a host, a subsystem and a transmission interface, the method comprising:

the host transmitting data to a memory of the subsystem via the transmission interface;

the subsystem generating an indication message transmitted to the host via the transmission interface according to memory utilization; and

controlling data transmission from the host to the subsystem according to the indication message;

wherein the step of controlling data transmission from the host to the subsystem according to the indication message comprises adjusting a size of a data packet transmitted from the host to the subsystem according to the memory utilization indicated by the indication message;

wherein the step of the subsystem generating the indication message transmitted to the host via the transmission interface according to the memory utilization comprises:

generating a sliding window;

adjusting a length of the sliding window for recording a storage value of the memory according to each received data and transmitted data; and

the subsystem generating the indication message transmitted to the host via the transmission interface according to the length of the sliding window.

7. The method of claim 6 , wherein the step of the subsystem generating the indication message transmitted to the host via the transmission interface according to the memory utilization comprises: setting a high storage threshold and a low storage threshold for the memory; and comparing the storage value of the memory with the high storage threshold and the low storage threshold for generating the indication message transmitted to the host via the transmission interface.

8. The method of claim 7 , wherein the step of controlling data transmission from the host to the subsystem according to the indication message further comprises stopping the host to transmit data to the memory of the subsystem via the transmission interface when the indication message indicates that the storage value is above the high storage threshold.

9. The method of claim 8 further comprising resuming the host to transmit data to the memory of the subsystem via the transmission interface when the indication message indicates that the storage value decreases from above the high storage threshold to below the low storage threshold.

10. The method of claim 6 , wherein a step of adjusting the length of the sliding window for recording the storage value of the memory according to each received data and transmitted data of the memory is increasing the length of the sliding window when the memory receives a data and decreasing the length of the sliding window when the memory outputs a data, for recording the storage value of the memory.

11. The method of claim 10 , wherein the step of controlling data transmission from the host to the subsystem according to the indication message further comprises stopping the host to transmit data to the memory of the subsystem of the subsystem via the transmission interface when the indication message indicates that the length of the sliding window is above a default value.

12. The method of claim 11 further comprising resuming the host to transmit data to the memory of the subsystem via the transmission interface when the indication message indicates that the length of the sliding window decreases from above the default value to below the default value.

13. The method of claim 6 , wherein the step of adjusting the length of the sliding window for recording the storage value of the memory according to each received data and transmitted data of the memory is decreasing the length of the sliding window when the memory receives a data and increasing the length of the sliding window when the memory outputs a data, for recording the storage value of the memory.

14. The method of claim 13 , wherein the step of controlling data transmission from the host to the subsystem according to the indication message further comprises stopping the host to transmit data to the memory of the subsystem via the transmission interface when the indication message indicates that the length of the sliding window is below a default value.

15. The method of claim 14 further comprising resuming the host to transmit data to the memory of the subsystem via the transmission interface when the indication message indicates that the length of the sliding window increases from below the default value to above the default value.

16. The method of claim 6 , wherein the indication message is carried in a packet.

17. The method of claim 6 , wherein a data processing rate of the subsystem is higher than a data transmission rate of the transmission interface.