Method for unit distance encoding of asynchronous pointers for non-power-of-two sized buffers

Abstract

A technique for encoding index values of asynchronous pointers for a non-power-of-two sized buffer that supports the unit distance property. The technique includes converting N+1 pointer index values corresponding to index locations 0 through N of the buffer from the natural binary-coded decimal format to a unit distance code format such as the gray code, adding a 0 bit in the MSB position of each of the N+1 converted pointer index values, adding a first pointer index value at index location N+1 equal to the pointer index value at index location N except that a 1 bit replaces the 0 bit in the MSB position, and adding a plurality of pointer index values at index locations greater than N+1 but less than or equal to N+n+1 that are equal to the first added pointer index value, where “n” equals the number of bits in each pointer index value prior to conversion. The 1 bits of the plurality of added pointer index values, starting with the LSB position and continuing with bit positions nearest the LSB, are then successively cleared until the pointer index value corresponding to the highest index location has a 1 bit in the MSB position and 0 bits in the remaining bit positions.