Abstract:
A method of operation in a memory controller is disclosed. The method includes receiving a strobe signal having a first phase relationship with respect to first data propagating on a first data line, and a second phase relationship with respect to second data propagating on a second data line. A first sample signal is generated based on the first phase relationship and a second sample signal is generated based on the second phase relationship. The first data signal is received using a first receiver clocked by the first sample signal. The second data signal is received using a second receiver clocked by the second sample signal.
Abstract:
This disclosure provides for adjustment of memory IO timing using a voltage controlled oscillator (VCO) and a register that generates a VCO control voltage directly used to vary memory IO timing. The register may be externally programmable by a controller and may be located on a memory device (IC, module or other device) or on an external voltage generator, which then provides an adjustable voltage to the memory device. This structure may be used to adjust memory timing so as to achieve a minimum target bitrate and thus minimize frequency of operation to minimize power. In one embodiment, each of several memory devices may be independently adjusted in this way to achieve a mesochronous memory system; in another embodiment, memory devices may be have their timing adjusted in parallel, with all memory devices equal to or greater than a target bitrate. Teachings presented herein provide a way to relax overdesign requirements and “tune” fast-fast and slow-slow devices to effectively operate as typical devices.
Abstract:
A memory controller is disclosed that provides refresh control circuitry to generate first refresh commands directed to a first row of storage cells within a memory device at a first rate. The refresh control circuitry generates second refresh commands directed to a second row of storage cells within the memory device at a second rate. Output circuitry outputs the first and second refresh commands to the memory device.
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.
Abstract:
The semiconductor device system includes multiple stacked substantially identical semiconductor devices each including a first side and an opposing second side. First and second pads are disposed at the first side of the semiconductor device, while third and fourth pads are disposed at the second side of the semiconductor device. First interface circuit is electrically coupled to the first pad and the third pad, while second interface circuit is electrically coupled to the second pad and the fourth pad. The second interface circuit is separate and distinct from the first interface circuit. At least one first semiconductor device of the multiple semiconductor devices is offset from other of the multiple semiconductor devices such that the fourth pad on the first semiconductor device is aligned with, and electrically connected to, the first pad on an adjacent one of the multiple semiconductor devices. In some embodiments, the first pad is associated with a first capacitance, while the second pad is associated with a second capacitance that is smaller than the first capacitance.
Abstract:
In a system, a memory bus has a first bus segment coupled to a memory controller that includes control logic and a first memory device, a second bus segment coupled to a second memory device, and a switch to selectively couple and decouple the first bus segment and the second bus segment in response to control information from the control logic. Note that the control logic may output control information to the switch to selectively decouple the first bus segment and the second bus segment to effect a change in an electrical length of the memory bus to enable data transfer with respect to the first memory device at a first data rate. Additionally, the control logic may output control information to the switch to selectively couple the first bus segment and the second bus segment to effect another change in the electrical length of the memory bus to enable data transfer with respect to the second memory device at a second data rate that is slower than the first data rate.
Abstract:
A communication channel is operated by storing a calibrated parameter value in nonvolatile memory during manufacturing, testing, or during a first operation of the device. Upon starting operation of the communication channel in the field, the calibrated parameter value is obtained from the nonvolatile memory, and used in applying an operating parameter of the communication channel. After applying the operating parameter, communication is initiated on a communication channel. The operating parameter can be adjusted to account for drift immediately after starting up, or periodically. The process of starting operation in the field includes power up events after a power management operation. In embodiments where one component includes memory, steps can be taken prior to a power management operation using the communication channel, such as transferring calibration patterns to be used in calibration procedures.
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.
Abstract:
An integrated circuit input/output interface with empirically determined delay matching is disclosed. In one embodiment, the integrated circuit input/output interface uses empirical information of the signal traces to adjust the transmit/receive clock of each pin of the interface so as to compensate for delay mismatches caused by differences in signal trace lengths. The empirical information, in one embodiment, includes signal flight time of each signal trace, which can be pre-measured or pre-calculated from known signal trace lengths. The empirical information, in another embodiment, includes trace-specific phase offset values calculated from pre-calculated or pre-measured signal flight times or signal trace lengths. In yet another embodiment, a transmitting device generates a set of serially delayed write clocks, which are used to control symbol transmission over signal traces so as to reduce simultaneous switching output noise and ground bound in the transmitting device.
Abstract:
Systems and methods for strobe signal timing calibration and control in strobe-based memory systems are provided below. These strobe-offset control systems and methods receive a strobe signal from a memory device and in turn automatically generate separate per-bit strobe signals for use in receiving data on each data line of a memory system. The systems/methods generate the optimal per-bit strobe signals by automatically calibrating per-bit offset timing between data signals of individual data bits and corresponding strobe signals. The strobe-offset control system effectively removes the detected phase difference between the data signal and the strobe signal.