US 12,355,503 B2
Calibration apparatus for a communication system
Guillaume Mouret, Portet-sur-Garonne (FR); Yann Cargouet, Portet sur Garonne (FR); and Tristan Bosvieux, Plaisance du Touch (FR)
Assigned to NXP USA, Inc., Austin, TX (US)
Filed by NXP USA, INC., Austin, TX (US)
Filed on Aug. 8, 2023, as Appl. No. 18/366,731.
Claims priority of application No. 22306236 (EP), filed on Aug. 18, 2022.
Prior Publication US 2024/0063925 A1, Feb. 22, 2024
Int. Cl. H04B 17/11 (2015.01); H04B 17/21 (2015.01); H04L 25/02 (2006.01)
CPC H04B 17/22 (2023.05) [H04B 17/11 (2015.01)] 20 Claims
OG exemplary drawing
 
1. A calibration apparatus for a communication system, wherein the communication system comprises:
a transmitter;
a receiver, which comprises a variable termination-resistance; and
a line for communicating differential voltage signals between the transmitter and the receiver;
wherein the calibration apparatus is configured to:
a) set the variable termination-resistance to a predetermined value;
b) cause the transmitter to send a calibration pattern to the receiver by:
setting the differential voltage on the line to a non-zero value during a non-zero-phase; and
setting the differential voltage on the line to zero during a subsequent zero-phase;
c) compare the differential voltage on the line during the zero-phase with a reduced-bit-value-threshold, wherein the reduced-bit-value-threshold is less than a bit-value-threshold that is used during active communication; and
if the differential voltage on the line during the zero-phase exceeds the reduced-bit-value-threshold, then adjust the value of the variable termination-resistance and return to step b); or
if the differential voltage on the line during the zero-phase does not exceed the reduced-bit-value-threshold, then store the current value of the variable termination-resistance for subsequent use during active communication.