A digital logic interface circuit makes use of a logic signal representative
of
a logic signaling level definition, to determine the logic swing amplitude of signals
from a given source adopting the same logic signaling level definition. The digital
logic interface circuit generates a threshold level from the logic swing amplitude
thus determined, and compares digital logic input signals against the threshold
level in order to discriminate different logic levels in the digital logic input
signals. The comparison result is provided as digital interface output signals
adopting a predetermined logic signaling level definition for use by subsequent
system sections. Examples of such representative signals are the digital input
logic signals themselves, clock signals or line encoded signals. Other examples
can be mode control signals or NRZ signals.
