Method and system for implementing relative time discriminations in a high speed data transmission network

Claim 1

For use in a system including a timer, comprising a free running n-bit wraparound counter having a finite timer period, said timer counting from a maximum negative value having a predetermined absolute value to a maximum positive value having the same predetermined absolute value, and wherein the time of of an event is recorded as the current count in said timer when the event occurred, a method of determining which of two events occurring within a single timer period was the earlier, said method comprising the steps of: a) setting a first value A equal to the two most significant bits (MSBs) of a first timer count recorded when one of the two events occurred; b) setting a second value B equal to the two MSBs of a second timer count recorded when the other of the events occurred; c) setting a third value equal to binary 1 if the MSBs of A and B have the same binary value and if the MSB of the binary result of A minus B equals binary 1; d) setting a fourth value equal to binary 1 if the MSBs of A and B have different binary values and the second MSB of A equals binary 1; e) setting a fifth value equal to binary 1 if the MSBs of A an B have different binary values and the second MSB of B equals binary 0; f) If any of the third, fourth and fifth values equals binary 1, designating one of the first and second timer counts as being the first to occur; and g) if none of the third, fourth and fifith values equals binary 1, designating the other of the first and second timer counts as being the first to occur.