a method of calibrating a data signal receiver configured to receive a multi - bit data signal and an associated data strobe signal , wherein transitions of the data strobe signal indicate sample points for the multi - bit data signal . the method comprises the steps of : receiving , on each bit of the multi - bit data signal , a sample of a predetermined data pattern ; determining , for each bit of the multi - bit data signal , a relative start timing value indicative of a start of the predetermined data pattern ; determining , for each bit of the multi - bit data signal , a relative end timing value indicative of an end of the predetermined data pattern ; determining , for each bit of the multi - bit data signal , a mid - point timing value halfway between the relative start timing value and the relative end timing value ; applying a bit timing delay to each bit of the multi - bit data signal such that the mid - point timing values are aligned ; and applying a strobe timing delay to the associated data strobe signal to align the associated data strobe signal with the aligned mid - point timing values .