Apparatus for source-synchronous information transfer and associated methods
AssigneeAltera Corporation
InventorsRyan Fung, Joshua David Fender
Life of this patent
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Abstract
An apparatus includes an interface circuit coupled to an electronic device. The interface circuit provides source synchronous communication with the electronic device using a strobe signal. The interface circuit is configured to gate the strobe signal in order to successfully communicate with the electronic device.
Claims19
Interface circuitry configured to perform source synchronous communication with an electronic device using a raw strobe signal, the interface circuitry comprising:
- a register, wherein the register has a clock input configured to receive the raw strobe signal, an input configured to receive an input signal, an output configured to provide an output signal, and a set input;
- and
- a shift circuit configured to shift an enable signal associated with the raw strobe signal to generate a shifted enable signal, wherein the set input of the register is configured to receive the shifted enable signal, wherein the register is configured to generate the output signal independent of a state of the input signal received at the input when the shifted enable signal is asserted, and wherein the interface circuitry is configured to generate a gated strobe signal by gating the raw strobe signal based at least partially on the shifted enable signal.
A system, comprising:
- an electronic device configured to use a raw strobe signal to communicate in a source synchronous manner;
- and
- an interface circuit that is coupled to the electronic device and that is configured to receive the raw strobe signal, wherein the interface circuit is configured to gate the raw strobe signal to generate a gated strobe signal, the interface circuit comprising:
- a register, wherein the register has a clock input configured to receive the raw strobe signal, an input, an output, and a set input;
- a first logic gate, wherein the first logic gate has an input coupled to the output of the register and wherein the first logic gate comprises a logic OR gate;
- and
- a second logic gate, wherein the second logic gate has a first input configured to receive the raw strobe signal and a second input coupled to an output of the first logic gate, wherein the second logic gate comprises a logic NAND gate.
Interface circuitry configured to perform source synchronous communication with an electronic device using a raw strobe signal received from the electronic device, the interface circuitry comprising:
- a register that is clocked using the raw strobe signal, wherein the interface circuitry is configured to gate the raw strobe signal to generate a gated strobe signal;
- a logic gate, wherein the logic gate has a first input that receives a raw signal that is different from the raw strobe signal and a second input that receives a configuration bit that is different from the raw strobe signal, and wherein the logic gate is configured to generate an output signal based on the configuration bit and the raw signal;
- and
- a shift circuit configured to shift the output signal generated by the logic gate to generate a shifted enable signal, wherein the register is configured to receive the shifted enable signal generated by the shift circuit.
Dependencies are inferred from the claim text.