Efficient lossless compression for peripheral interface data transfer

A touchscreen interface, comprising:

• a communications interface adapted to communicate data over a serial bus;
• and
• a touchscreen controller configured to:
• receive touchscreen data comprising node values representative of signals generated by a touchscreen panel;
• calculate difference values for the node values, each difference value representing a difference between one of the node values and a different node-related value;
• determine a bit size for words to be used for storing the difference values;
• generate a first data frame comprising the difference values;
• and
• transmit the first data frame over a control data bus,
• wherein a receiver of the first data frame is adapted to reconstruct the touchscreen data without information loss using a plurality of node values provided in one or more previously transmitted frames, the one or more previously transmitted frames including at least one uncompressed frame.

A method for processing touchscreen information, comprising:

• receiving a plurality of frames from a serial bus, the plurality of frames comprising at least one compressed frame;
• decompressing the at least one compressed frame to obtain node values representative of signals generated by a touchscreen panel,
• wherein the node values are lossless copies of corresponding node values compressed by a transmitter of the plurality of frames, and
• wherein the compressed frame has a predefined size.

An apparatus comprising:

• means for receiving a plurality of frames from a serial bus, the plurality of frames comprising at least one compressed frame;
• and
• means for decompressing the at least one compressed frame to obtain node values representative of signals generated by a touchscreen panel,
• wherein the node values are lossless copies of corresponding node values compressed by a transmitter of the plurality of frames, and
• wherein the compressed frame has a predefined size.