Selectable-tap equalizer
AssigneeRambus Inc.
InventorsJared L. Zerbe, Vladimir M. Stojanovic, Fred F. Chen
Life of this patent
Estimating the term…
Abstract
A signaling circuit having a selectable-tap equalizer. The signaling circuit includes a buffer, a select circuit and an equalizing circuit. The buffer is used to store a plurality of data values that correspond to data signals transmitted on a signaling path during a first time interval. The select circuit is coupled to the buffer to select a subset of data values from the plurality of data values according to a select value. The equalizing circuit is coupled to receive the subset of data values from the select circuit and is adapted to adjust, according to the subset of data values, a signal level that corresponds to a data signal transmitted on the signaling path during a second time interval.
Claims20
A method of setting a parameter to be used in a normal mode of operation of a signaling system to transfer data between a first integrated circuit and a second integrated circuit of the signaling system, the first integrated circuit to be connected with the second integrated circuit via a conductive signal path, the method comprising, in a calibration mode:
- exchanging a sequence of symbols between the first integrated circuit and the second integrated circuit, wherein exchanging the sequence symbols comprises using respective values of a clock phase;
- for each of the respective values of the clock phase, comparing sampled values corresponding to the exchanged sequence of symbols with an expected sequence, to obtain pass/fail information for the respective clock phase;
- using the pass/fail information to determine a range of the respective values of the clock phase for which the sequence of symbols is correctly exchanged between the first integrated circuit and the second integrated circuit;
- and
- receiving a specific value of the parameter, dependent on the range, to be applied in transferring the data during the normal mode.
An apparatus for setting a parameter to be used in a normal mode of operation of a signaling system to transfer data between a first integrated circuit and a second integrated circuit of the signaling system, the first integrated circuit to be connected with the second integrated circuit via a conductive signal path, the apparatus comprising:
- exchange circuitry to exchange during a calibration mode a sequence of symbols between the first integrated circuit and the second integrated circuit, using respective values of a clock phase;
- comparison circuitry to, for each of the respective values of the clock phase, compare sampled values corresponding to the exchanged sequence of symbols with an expected sequence, to obtain pass/fail information;
- circuitry to identify a range of the respective values of the clock phase for which the sequence of symbols is correctly exchanged between the first integrated circuit and the second integrated circuit, based on the pass/fail information;
- and
- circuitry to receive a specific value of the parameter, dependent on the range, to be applied in transferring the data during the normal mode.
An apparatus for setting a parameter to be used in a normal mode of operation of a signaling system to transfer data between a first integrated circuit and a second integrated circuit of the signaling system, the first integrated circuit to be connected with the second integrated circuit via a conductive signal path, the apparatus comprising:
- exchange circuitry to receive during a calibration mode a sequence of symbols from a first one of the first integrated circuit and the second integrated circuit, using respective values of a clock phase;
- comparison circuitry to, for each of the respective values of the clock phase, compare sampled values corresponding to the received sequence of symbols with an expected sequence, to obtain pass/fail information;
- circuitry to identify a range of the respective values of the clock phase for which the sequence of symbols is correctly received from the first one, based on the pass/fail information;
- and
- circuitry to set a specific value of the parameter, dependent on the range, to be applied in transferring the data during the normal mode.
Dependencies are inferred from the claim text.