System and method for jitter compensation in data transfers

A method for buffering data in a device configured to be coupled to other devices in a loop network topology, the method comprising:

• writing a plurality of successive words into storage locations in a circular memory indicated by a write pointer;
• reading the plurality of successive words out of storage locations in the circular memory indicated by a read pointer;
• determining a number of storage locations by which the write pointer leads the read pointer;
• reading one of the storage locations which contains a fill word two or more consecutive times in response to detecting that the number of storage locations by which the write pointer leads the read pointer is less than a predetermined minimum number;
• and
• overwriting one of the storage locations which contains a fill word one or more times in response to detecting that the number of storage locations by which the write pointer leads the read pointer is greater than a predetermined maximum number.

A device configured to be installed in a network having a loop topology, the device comprising:

• an input port for receiving incoming data from a preceding device in the loop, wherein the incoming data is clocked by an external clock signal;
• an output port for transmitting outgoing data to a subsequent device in the loop, wherein the outgoing data is clocked by an internal clock signal;
• a circular buffer having a plurality of storage locations, wherein the circular buffer is coupled to the input and output ports and configured to store data in the plurality of storage locations;
• write logic coupled to the input port and the circular buffer, wherein the write logic is configured to write received data to storage locations in the circular buffer indicated by a write pointer, wherein the write pointer is advanced after data is written to the indicated storage locations, and wherein data is written to the circular buffer at rate of the external clock signal;
• read logic coupled to the output port and the circular buffer, wherein the read logic is configured to read data from the storage locations in the circular buffer indicated by a read pointer and transmit the read data to the output port, wherein the read pointer is advanced after data is read from the indicated storage locations, and wherein data is read from the circular buffer at rate of the internal clock signal;
• and
• control logic configured to determine whether the read logic is reading data out of the circular buffer more quickly or more slowly than the write logic is writing data into the circular buffer, wherein if the read logic is reading data out of the circular buffer more quickly or more slowly than the write logic is writing data into the circular buffer, the control logic is configured to modify the position of at least one of the read and write pointers to compensate therefor.

A buffer system comprising:

• a circular buffer configured to store data in a plurality of storage locations, wherein a write position is indicated in the buffer by a write pointer and a read position is indicated in the buffer by a read pointer;
• write logic configured to write received data to the storage location indicated by the write pointer;
• read logic configured to read data from the storage location indicated by the read pointer;
• and
• control logic configured to adjust the read pointer to cause a fill word to be read twice in response to detecting that the write pointer leads the read pointer by less than a predetermined minimum amount and configured to adjust the write pointer to cause a fill word to be deleted in response to detecting that the write pointer leads the read pointer by more than a predetermined maximum amount.