US 6,570,944 B2 · Apparatus for data recovery in a synchronous chip-to-chip system

Abstract

An apparatus that reduces sampling errors for data communicated between devices uses phase information acquired from a timing reference signal such as a strobe signal to align a data-sampling signal for sampling a data signal that was sent along with the timing reference signal. The data-sampling signal may be provided by adjustably delaying a clock signal according to the phase information acquired from the strobe signal. The data-sampling signal may also have an improved waveform compared to the timing reference signal, including a fifty percent duty cycle and sharp transitions. The phase information acquired from the timing reference signal may also be used for other purposes, such as aligning received data with a local clock domain, or transmitting data so that it arrives at a remote device in synchronism with a reference clock signal at the remote device.

Claims27

Dependent claims

An apparatus comprising:

a variable delay circuit to generate a data-sampling signal that is delayed relative to a reference clock signal according to a delay control signal;
a control circuit coupled to receive the data-sampling signal from the variable delay circuit and to receive a timing reference signal from a data transmitting device, the control circuit including circuitry to determine a phase difference between the data-sampling signal and the timing reference signal and to generate the delay control signal according to the phase difference;
and
a receive circuit coupled to receive the data-sampling signal from the variable delay circuit and to receive a data signal from the data transmitting device, the receive circuit including circuitry to sample the data signal in response to a transition of the data-sampling signal.

1 more element

Dependencies are inferred from the claim text.

Apparatus for data recovery in a synchronous chip-to-chip system

Life of this patent

Apparatus for data recovery in a synchronous chip-to-chip system

Life of this patent

Abstract

Claims27