摘要:
A random access memory system has a memory controller, a first memory device, a second memory device, and a memory bus. The memory controller is configured to control access to a plurality of memory devices. The memory bus is configured to alternatively couple the memory controller to the first memory device and to couple the memory controller to the second memory.
摘要:
Methods and apparatus for controlling a shared bus. The shared bus is shared between a volatile memory device via a nonvolatile memory interface of the volatile memory and two or more nonvolatile memory controllers. In one embodiment, a method includes receiving a request from a first nonvolatile memory controller of the two or more nonvolatile memory controllers for control of the shared bus. In response to receiving the request, control of the shared bus is granted to the first nonvolatile memory controller if the priority for each of the two or more nonvolatile memory controllers indicates that control should be granted. When control is granted to the first nonvolatile memory controller, the first nonvolatile memory controller is the only nonvolatile memory controller of the two or more nonvolatile memory controllers which performs data access operations via the shared bus.
摘要:
Methods and apparatus for accessing multiple memory arrays within a memory device using multiple sets of address/data lines are provided. The memory arrays may be accessed independently, using separate addresses, in one mode of operation, and accessed using a common single address in another mode of operation.
摘要:
A memory comprising a memory array, an address buffer configured to receive an external address, a refresh address counter configured to generate a refresh address, a first circuit configured to detect a distance between the external address and refresh address, and a second circuit configured to generate at least one timing signal for accessing data associated with the external address from the memory array in response to the distance is provided.
摘要:
The refresh address generator of a memory includes, in part, a counter, a multitude of shift registers and multiplexers, and a comparator. With each clock cycle, the counter increments and stores the refresh count address, and the addresses stored in the counter and the shift registers prior to the increment operation is shifted out and stored in a pipelined fashion. If the array address stored in the last stage of the register pipeline is equal to the address of the array read out during the cycle immediately preceding the refresh cycle or is equal to the address of the neighboring array of the read out array, the comparator causes multiplexer to select the address stored in the counter as the refresh address. This address differs from the address of the array read out during the immediately preceding cycle by at least two counts.
摘要:
A method and a circuit configuration for implementing a double data rate feature in a memory device capable of operating in a variable latency mode. The memory device may utilize a WAIT_DQS signal that combines functionality of a WAIT signal indicating when valid data is present on a data bus in Read cycle and the memory is ready to accept data in Write cycle, and a data strobe (DQS) signal.
摘要:
Methods and circuit configurations for refreshing data in a semiconductor memory device in which refresh operations are performed for a limited number of rows. The limited number of rows may include only those rows that contain valid data, for example, as determined by monitored write operations.
摘要:
One embodiment of the present invention provides a semiconductor memory including a bank of N memory arrays each having a corresponding array address, a bus providing an array address signal, a row address signal (RAS), and timing signals. The semiconductor memory further includes N tracking circuits each coupled between a different one of the N memory arrays and the bus. A first tracking circuit, in response to receiving a first array address for a first array via the array address signal and a first active state of the RAS, couples the first array to the bus such that only the first array responds to a first sequence of timing signals constituting a first bank transaction. A second tracking circuit, in response to receiving a second array address for a second array via the array address signal and a second active state of the RAS, couples the second array to the bus such that only the second array begins responding to second sequence of timing signals constituting a second bank transaction before the first bank transaction is complete.
摘要:
A significantly more efficient implementation of a DLL for systems using two separate clock signals, whereby a single DLL circuit is used to provide for locking of both clock signals. According to the present invention, the input to the DLL is controlled such that it responds to edges of both clock signals. The present invention provides a circuit receiving a first periodic signal CLK1 and a second periodic signal CLK2, there being a phase difference between CLK1 and CLK2, the circuit including a delay-locked loop (DLL) having one delay path, wherein the same delay path provides delay tuning for both CLK1 and CLK2.
摘要:
A counter system has a first counter seeded by several input signals and a second counter seeded by at least a first output from the first counter. A selection signal is input to the second counter to select the use of either an interleaved count sequence or a sequential count sequence.