Systems and methods for measuring signal propagation delay between circuits
AssigneeIntel Corporation
InventorHarry Muljono
Life of this patent
Estimating the term…
Abstract
Embodiments include systems and methods for measurement of signal propagation delay between Input/Output (IO) Loopback (IOLB) circuits. Embodiments include measurement of an output delay time of a first IOLB circuit and measurement of an input delay time of a second IOLB circuit. Embodiments also include measurement of a total delay time from an internal point of the first IOLB circuit to an internal point of the second IOLB circuit. Embodiments subtract from the measured total delay time, the measured output delay time of the first IOLB circuit and the measured input delay time of the second IOLB circuit to determine the time of flight of a signal between the I/O pads of the two IOLB circuits.
Claims20
A method for determining the time of flight from the I/O pad of a first Input/Output (IO) Loopback (IOLB) circuit to the I/O pad of a second IOLB circuit, comprising:
- determining an internal output delay time of the first IOLB circuit, wherein the internal output delay time represents propagation delay from a first point internal to the first IOLB circuit to the output pad of the first IOLB;
- determining an internal input delay time of the second IOLB circuit;
- wherein the internal input delay time represents propagation delay from the I/O pad of the second
- measuring a total delay time from the first point internal to the first IOLB circuit to the second point internal to the second IOLB circuit;
- and
- subtracting from the measured total delay time the internal output delay time and the internal input delay time to determine a time of flight between the I/O pads of the first and second IOLB circuits.
An Input/Output (IO) Loopback (IOLB) circuit with an I/O pad, comprising:
- an output path from a first internal point of the IOLB circuit to the I/O pad of the
- a pattern generator to generate a first test signal to be propagated through the output path to the I/O pad of the IOLB circuit;
- a multiplexer in an input path to select as an output one of a plurality of inputs, one input receiving a signal from the I/O pad of the IOLB circuit, and another input receiving a second test signal;
- an input path from an input of the multiplexer to a second internal point of the IOLB circuit;
- and
- a comparator to receive at a first of its inputs one of the first and second test signals and to receive at a second of its inputs a reference signal from the pattern generator, wherein the comparator determines a first propagation time of the first test signal along the output path and the input path, and determines a second propagation time of the second test signal along the input path.
A test system for measuring times of flight between Input/Output (IO) Loopback (IOLB) circuits, comprising
- a plurality of IOLB circuits, each with a mechanism for determining an input delay time and an output delay time;
- and
- a controller to select two IOLB circuits and to determine a time of flight there between by measuring a total delay time and subtracting both an output delay time of a first of the two IOLB circuits and an input delay time of the second IOLB circuit.
Dependencies are inferred from the claim text.