摘要:
A physical memory interface (Phy) and method of operating is disclosed. The Phy interface includes command and status registers (CSRs) configured to receive a first power context and second power context. Selection circuitry is configured to switch between the first and second power contexts. A plurality of adjustable delay elements are provided, each having a delay time responsive to the selected power context. A first set of CSRs configured may store the first power context and a second set of CSRs configured may store the second power context. The Phy interface may also include a plurality of drivers each having a selectable drive strength responsive to the selected power context. The Phy interface may also include a plurality of receivers each having a selectable termination impedance responsive to the selected power context. Switching between power contexts may result in adjusting of the delay elements, drive strength and/or termination impedance of one or more drivers/receivers.
摘要:
A physical memory interface (Phy) and method of operating is disclosed. The Phy interface includes command and status registers (CSRs) configured to receive a first power context and second power context. Selection circuitry is configured to switch between the first and second power contexts. A plurality of adjustable delay elements are provided, each having a delay time responsive to the selected power context. A first set of CSRs configured may store the first power context and a second set of CSRs configured may store the second power context. The Phy interface may also include a plurality of drivers each having a selectable drive strength responsive to the selected power context. The Phy interface may also include a plurality of receivers each having a selectable termination impedance responsive to the selected power context. Switching between power contexts may result in adjusting of the delay elements, drive strength and/or termination impedance of one or more drivers/receivers.
摘要:
A transceiver (222) includes a receive circuit (320), a transmit circuit (340), a shared delay locked loop (DLL) (360), and a controller (210). The receive circuit (320) has a first input coupled to an external data terminal, a second input coupled to an external data strobe terminal, and an output coupled to an internal data terminal. The transmit circuit (340) has a first input coupled to the internal data terminal, a second input for receiving an internal clock signal, a first output coupled to the external data terminal, and a second output coupled to the external data strobe terminal. The controller (210) enables the shared DLL (360) for use by the receive circuit (320) during a receive cycle, and enables the shared DLL (360) for use by the transmit circuit (340) during a transmit cycle.
摘要:
A data driver includes a first latch (322), an extension logic circuit (324), and a second latch (330). The first latch (322) has an input for receiving an input data signal, a clock input for receiving a first clock signal, and an output. The extension logic circuit (324) has an input coupled to the output of the first latch (322), a control input for receiving a control signal, and an output. The extension logic circuit (324) selectively delays the output of the first latch (322) in response to the control signal. The second latch (330) has an input coupled to the output of the extension logic circuit (324), a clock input for receiving a second clock signal, and an output for providing an output data signal.
摘要:
A receive circuit (320) includes a DLL core (510), a latch (326), and a DLL control circuit (520). The DLL core (510) has a first input for receiving a DLL clock signal, a second input for receiving a delay line select signal, and an output for providing a delayed data strobe signal. The latch (326) has a signal input for receiving an external data signal, a control input coupled to the output of the DLL core (510), and an output for providing an internal data signal. The DLL control circuit (520) provides the DLL clock signal to the first input of the DLL core (510) responsive to a memory data strobe signal while the receive circuit is in a first mode, and provides the DLL clock signal to the first input of the DLL core (510) responsive to a processor clock signal while the receive circuit (320) is in a second mode.
摘要:
A data driver includes a first latch (322), an extension logic circuit (324), and a second latch (330). The first latch (322) has an input for receiving an input data signal, a clock input for receiving a first clock signal, and an output. The extension logic circuit (324) has an input coupled to the output of the first latch (322), a control input for receiving a control signal, and an output. The extension logic circuit (324) selectively delays the output of the first latch (322) in response to the control signal. The second latch (330) has an input coupled to the output of the extension logic circuit (324), a clock input for receiving a second clock signal, and an output for providing an output data signal.
摘要:
A transceiver (222) includes a receive circuit (320), a transmit circuit (340), a shared delay locked loop (DLL) (360), and a controller (210). The receive circuit (320) has a first input coupled to an external data terminal, a second input coupled to an external data strobe terminal, and an output coupled to an internal data terminal. The transmit circuit (340) has a first input coupled to the internal data terminal, a second input for receiving an internal clock signal, a first output coupled to the external data terminal, and a second output coupled to the external data strobe terminal. The controller (210) enables the shared DLL (360) for use by the receive circuit (320) during a receive cycle, and enables the shared DLL (360) for use by the transmit circuit (340) during a transmit cycle.
摘要:
A receive circuit (320) includes a DLL core (510), a latch (326), and a DLL control circuit (520). The DLL core (510) has a first input for receiving a DLL clock signal, a second input for receiving a delay line select signal, and an output for providing a delayed data strobe signal. The latch (326) has a signal input for receiving an external data signal, a control input coupled to the output of the DLL core (510), and an output for providing an internal data signal. The DLL control circuit (520) provides the DLL clock signal to the first input of the DLL core (510) responsive to a memory data strobe signal while the receive circuit is in a first mode, and provides the DLL clock signal to the first input of the DLL core (510) responsive to a processor clock signal while the receive circuit (320) is in a second mode.