Patent ID: 7535382

Claim:
A counter for keeping track of a changing position of a displacement transducer that outputs quadrature signals, the counter comprising: a fast tracking counter portion configured to input the quadrature signals and operate at a first clock rate CR1 and output position information comprising a first number N of less significant bits corresponding to the position of the displacement transducer; a slow tracking counter portion configured to input the N less significant bits from the fast tracking counter portion and operate at a second clock rate CR2 slower than the first clock rate and output position information comprising a second number P of more significant bits corresponding to the position of the displacement transducer; and a position correcting latch that configured to: input and latch the N less significant bits of position information from the fast tracking counter portion; input and latch at least the P more significant bits of position information from the slow tracking counter portion; combine the position information from the fast and slow tracking counter portions to provide (N+P) bits of resulting combined position information, wherein the N least significant bits of the (N+P) bits of resulting combined position information are the same as the latched N less significant bits of position information from the fast tracking counter portion; and output the (N+P) bits of resulting combined position information as a corrected latched position value.