摘要:
A transmission line interface circuit includes a voltage regulator to control a voltage swing of the transmission line interface circuit for signal transmission. The transmission line interface circuit includes complementary driver elements, including a p-type driver element to pull up the transmission line in response to a logic high, and an n-type driver element to pull down the transmission line in response to a logic low. The voltage regulator is coupled between one of the driver elements and a respective voltage reference to reduce a voltage swing of the transmission line interface circuit.
摘要:
An I/O interface supports scrambling, where the scrambling can include nonlinear scrambling of the scrambling code, or dynamic bus inversion of the scrambling code, or selective switching of selected bits of the scrambling code, or a combination of these. The transmitting device includes a scrambler and the receiving device includes a descrambler. Both the scrambler and the descrambler generate a linear feedback scrambling code modified by applying one or more of the techniques mentioned above. The modified scrambling code may cause fewer than half of the scrambled output bits to be toggled with respect to a previous scrambled output. The scrambler applies the modified scrambling code to a signal to transmit. The descrambler applies the modified scrambling code to a received signal.
摘要:
In a memory subsystem, a memory controller can put its physical interface (PHY) into a low power state when an associated memory device is in self-refresh. Instead of powering on the interface and then triggering the memory device to exit self-refresh, or instead waiting for the physical interface to be powered up prior to waking the memory device from self-refresh, the memory controller can instruct the PHY to send a self-refresh exit command to the memory device and power up the physical interface in parallel with the memory device coming out of self-refresh. The memory controller can power down a high speed clock path of the PHY and use a slower clock path to send the self-refresh exit command before powering the high speed clock path back up.
摘要:
A memory subsystem can test a memory device in situ, testing the performance of the device in the system it is built into during production. Thus, the refresh rate can be adjusted specific to the memory device(s) of a specific system, rather than defaulting to a refresh frequency specified by a standard for the memory device(s). A test component embedded within the host memory subsystem can perform a test and identify specific bits or lines of memory that produce errors when a lower frequency refresh rate is used. The system maps out the identified bits or lines to prevent the bits/lines from being used in runtime of the system. The memory subsystem can then set its refresh rate to an adjusted refresh rate at which a threshold number of errors can be removed by mapping out the bits/lines.
摘要:
Circuitry to provide a supply voltage. A voltage regulator is coupled to receive a target reference signal. The voltage regulator generates a supply voltage (Vtt) and is coupled to receive the supply voltage as an input signal. An upper limit comparator receives an upper limit voltage signal that is higher than the target reference voltage signal and the supply voltage to generate a “too high” signal when the supply voltage exceeds an upper threshold. A lower limit comparator receives a lower limit voltage signal that is lower than the target reference voltage signal and the supply voltage to generate a “too low” signal when the supply voltage is below a lower threshold. A pull up current source is coupled to pull the supply voltage up in response to the too low signal. A pull down current source is coupled to pull the supply voltage down in response to the too high signal.
摘要:
REUT (Robust Electrical Unified Testing) for memory links is introduced which speeds testing, tool development, and debug. In addition it provides training hooks that have enough performance to be used by BIOS to train parameters and conditions that have not been possible with past implementations. Address pattern generation circuitry is also disclosed.
摘要:
A memory subsystem triggers entry and exit of a memory device from low power mode with a chip select (CS) signal line. For a system where the command bus has no clock enable (CKE) signal line, the system can trigger low power modes with CS instead of CKE. The low power mode can include a powerdown state. The low power mode can include a self-refresh state. The memory device includes an interface to the command bus, and receives a CS signal combined with command encoding on the command bus to trigger a low power mode state change. The memory device can be configured to monitor the CS signal and selected other command signals while in low power mode. The system can send an ODT trigger while the memory device is in low power mode, even without a dedicated ODT signal line.
摘要:
Examples may include techniques for using a sample clock to measure a duty cycle by periodic sampling a target clock signal based on a prime number ratio of a reference clock frequency. The reference clock frequency used to set a measurement cycle time over which the duty cycle is to be measured. A magnitude of a duty cycle error as compared to a programmable target duty cycle is determined based on the measured duty cycle and the duty cycle is adjusted based, at least in part, on the magnitude of the duty cycle error.