Abstract:
Systems and methods for delay control are described herein. In one embodiment, a delay system comprises a first delay circuit configured to provide a voltage bias to a second delay circuit, wherein the voltage bias controls a delay of the second delay circuit, and to update the voltage bias at an update rate. The delay system also comprises an update controller configured to adjust the update rate of the first delay circuit. For example, the update controller may adjust the update rate based on timing requirements of a memory interface incorporating the delay system. The update rate may be reduced when the timing requirements are more relaxed to reduce power, and may be increased when the timing requirements are tighter.
Abstract:
Systems and methods for delaying a signal are described herein. In one embodiment, a method for delaying a signal comprises receiving a first signal edge, and, in response to receiving the first signal edge, counting a number of oscillations of an oscillator. The method also comprises outputting a second signal edge if the number of oscillations reaches a predetermined number. The second signal edge represents a delayed version of the first signal edge.
Abstract:
Programmable delay circuits are described herein according to embodiments of the present disclosure. In one embodiment, a delay circuit comprises a plurality of delay stages coupled in series. Each of the delay stages comprises a delay gate on a forward path of the delay circuit, wherein the delay gate is configured to pass or block a signal on the forward path depending on a logic state of a respective select signal. Each of the delay stages also comprises a multiplexer on a return path of the delay circuit, wherein the multiplexer is configured to pass a signal on the return path or route the signal on the forward path to the return path depending on the logic state of the respective select signal. Output logic states of the delay gates and the multiplexers may remain static during a change in the delay setting of the delay circuit to reduce glitch.
Abstract:
Systems and methods for delay control are described herein. In one embodiment, a delay circuit comprises a first delay path and a second delay path. The delay circuit also comprises a plurality of switches, wherein each switch is coupled between different points on the first and second delay paths, and each switch is configured to turn on or off in response to a respective one of a plurality of select signals. The delay circuit further comprises a multiplexer having a first input coupled to an output of the first delay path, a second input coupled to an output of the second delay path, and an output coupled to an output of the delay circuit, wherein the multiplexer is configured to selectively couple one of the outputs of the first and second delay paths to the output of the delay circuit in response to a second select signal.
Abstract:
Systems and methods for delay control are described herein. In one embodiment, a delay system comprises a first delay circuit configured to provide a voltage bias to a second delay circuit, wherein the voltage bias controls a delay of the second delay circuit, and to update the voltage bias at an update rate. The delay system also comprises an update controller configured to adjust the update rate of the first delay circuit. For example, the update controller may adjust the update rate based on timing requirements of a memory interface incorporating the delay system. The update rate may be reduced when the timing requirements are more relaxed to reduce power, and may be increased when the timing requirements are tighter.
Abstract:
Systems and methods for recovering clock and data from a data input signal are disclosed that sample a plurality of clock phase signals with the data input signal to determine a timing relationship between the data input signal and the clock phase signals and use the determined to timing relationship to select one of the clock phase signals to use for sampling the data input signal to produce recovered data. The CDR can include a glitch suppression module to suppress glitches on the clock output signal that could be caused by large instantaneous jitter on the data input signal. A clock and data recovery circuit (CDR) using these methods can quickly lock to a new data input signal and can reliably receive data when there is large instantaneous timing jitter on the data input signal.
Abstract:
Systems and methods for delaying a signal are described herein. In one embodiment, a method for delaying a signal comprises receiving a first signal edge, and, in response to receiving the first signal edge, counting a number of oscillations of an oscillator. The method also comprises outputting a second signal edge if the number of oscillations reaches a predetermined number. The second signal edge represents a delayed version of the first signal edge.
Abstract:
Programmable delay circuits are described herein according to embodiments of the present disclosure. In one embodiment, a delay circuit comprises a plurality of delay stages coupled in series. Each of the delay stages comprises a delay gate on a forward path of the delay circuit, wherein the delay gate is configured to pass or block a signal on the forward path depending on a logic state of a respective select signal. Each of the delay stages also comprises a multiplexer on a return path of the delay circuit, wherein the multiplexer is configured to pass a signal on the return path or route the signal on the forward path to the return path depending on the logic state of the respective select signal. Output logic states of the delay gates and the multiplexers may remain static during a change in the delay setting of the delay circuit to reduce glitch.
Abstract:
Systems and methods for delay control are described herein. In one embodiment, a delay circuit comprises a first delay path and a second delay path. The delay circuit also comprises a plurality of switches, wherein each switch is coupled between different points on the first and second delay paths, and each switch is configured to turn on or off in response to a respective one of a plurality of select signals. The delay circuit further comprises a multiplexer having a first input coupled to an output of the first delay path, a second input coupled to an output of the second delay path, and an output coupled to an output of the delay circuit, wherein the multiplexer is configured to selectively couple one of the outputs of the first and second delay paths to the output of the delay circuit in response to a second select signal.
Abstract:
Systems and methods for recovering clock and data from a data input signal are disclosed that sample a plurality of clock phase signals with the data input signal to determine a timing relationship between the data input signal and the clock phase signals and use the determined to timing relationship to select one of the clock phase signals to use for sampling the data input signal to produce recovered data. The CDR can include a glitch suppression module to suppress glitches on the clock output signal that could be caused by large instantaneous jitter on the data input signal. A clock and data recovery circuit (CDR) using these methods can quickly lock to a new data input signal and can reliably receive data when there is large instantaneous timing jitter on the data input signal.