Resources Contact Us Home
Bist DDR memory interface circuit and method for testing the same

Image Number 4 for United States Patent #8035407.

An apparatus and method for self-testing a DDR memory interface are disclosed. In one aspect, a built-in-self-test (BIST) memory interface circuit includes a signal multiplier for receiving a first clock signal from a tester and outputs a multiplied clock signal. A first multiplexer is used for selecting between a test mode and a normal operating mode and provides an output signal. A delay magnitude generator is coupled to the signal multiplier to receive the multiplied clock signal and provides a second clock signal and a phase control signal. A plurality of digitally controlled delay line blocks are used for each receiving the second clock signal and the phase control signal and outputting a phase shifted data strobe output signal in response to receiving an internal data strobe input signal. A second multiplexer selects one of the internal data strobe input signals and a third multiplexer selects the phase shifted data strobe output signal that corresponds to the selected internal data strobe input signal. A phase detector determines a phase difference between the selected internal data strobe input signal and the selected phase shifted data strobe output signal and outputs a phase difference value.

  Recently Added Patents
Gearbox housing
Determination of copy number variations using binomial probability calculations
Portable communication terminal, communication method and control program
Vehicle hood
Electrical event detection device and method of detecting and classifying electrical power usage
Memory cell and memory cell array using the same
Redistribution layer (RDL) with variable offset bumps
  Randomly Featured Patents
Method and apparatus for differentiating pedestrians, vehicles, and other objects
Sliding mechanism
Semiconductor memory device
Diphenylurea derivatives
Quadrupole mass spectrometer
Electric power busway plug alignment arrangement
Fixture for resurfacing vehicle brake discs
Data storage tape cartridge with hub alignment insert
Apparatus for separating aggregates from an asphalt-aggregate mixture
High strength, heat treatable aluminum alloy