Abstract: The present invention provides various techniques for optimized transfer of information in electronic systems involving memory devices to improve data bandwidth. The invention offers solutions to the problem of packing all of the required information including data, control and address information over a limited number of interconnect lines in an optimized fashion. In one embodiment, the present invention combines different control information, such as row address and bank address information into a unified address field wherein one or more bits can be shared. By sharing bits across various address fields, the present invention conserves bandwidth that is required by the control signals. In another embodiment, the present invention provides various schemes for defining and constructing packets of information that maximize the amount of information carried by a given packet across a limited number of interconnect lines.

Abstract: A method and apparatus for adjusting the performance of a memory system is provided. A memory control device comprises a master device including a frequency detector, a memory channel, and a memory device coupled to the master device via the memory channel. The memory device includes a decoder designed to receive a control signal from the master device. A clock recovery and alignment circuit receives the control signal from the decoder and adjusts the operating frequency of the memory device in response to the control signal.

Abstract: A method for reducing the communication overhead over the interface bus to the memory devices for refresh operations. This is done by refreshing multiple banks in response to a single command. Multibank refresh is made possible by varying the current profile for the row sense and row precharge currents during a refresh operation, as compared to normal memory access. Unlike normal memory accesses, data is not needed, and a fast access time is not required. This allows the current to be spread using different circuitry for driving the current to lessen current spikes. The spread current is still maintained within the timing of a normal memory access.

Abstract: A memory device includes an interconnect with mask pins and a memory core for storing data. A memory interface circuit is connected between the interconnect and the memory core. The memory interface circuit selectively processes write mask data from the mask pins or precharge instruction signals from the mask pins.

Abstract: A memory system includes an interconnect structure with a high speed channel and a low speed channel. A memory device with interface circuitry is coupled to the interconnect structure. The interface circuitry includes a high power interface for coupling to the high speed channel and a low power interface for coupling to the low speed channel. The memory device is operative in a low power mode and a high power mode. A memory controller is coupled to the high speed channel and the low speed channel of the interconnect structure. The memory controller is configured to transmit control information over the low speed channel to set the power mode of the memory device. The memory device is operative in a low power mode during which high power receiver circuits are turned off. The memory device is also operative in a nap mode during which an internal clock compensation circuit is left on to preserve phase information.

Abstract: A method and apparatus for storing data in a memory device is described. The apparatus is configured to perform the following steps. The method employs a two-step technique which allows the out-of-order completion of read and write operations. When a write operation requires a resource needed for the completion of a read operation, the data being written is stored in a write data buffer in the memory device. The write data is stored in the buffer until a datapath is available to communicate the data to the memory device's memory core. Once the resource is free (or the memory device, or its controller force the write to complete) the data is written to the memory core of the memory device using the now-free datapath.

Abstract: The present invention provides various techniques for optimized transfer of information in electronic systems involving memory devices to improve data bandwidth. The invention offers solutions to the problem of packing all of the required information including data, control and address information over a limited number of interconnect lines in an optimized fashion. In one embodiment, the present invention combines different control information, such as row address and bank address information into a unified address field wherein one or more bits can be shared. By sharing bits across various address fields, the present invention conserves bandwidth that is required by the control signals. In another embodiment, the present invention provides various schemes for defining and constructing packets of information that maximize the amount of information carried by a given packet across a limited number of interconnect lines.

Abstract: A memory system includes a set of memory devices. An interconnect structure links the set of memory devices to one another. A memory controller is connected to the interconnect structure. The memory controller is configured to apply a control signal to the interconnect structure such that a specified subset of the set of memory devices performs a refresh operation.

Abstract: A method for reducing the communication overhead over the interface bus to the memory devices for refresh operations. This is done by refreshing multiple banks in response to a single command. Multibank refresh is made possible by varying the current profile for the row sense and row precharge currents during a refresh operation, as compared to normal memory access. Unlike normal memory accesses, data is not needed, and a fast access time is not required. This allows the current to be spread using different circuitry for driving the current to lessen current spikes. The spread current is still maintained within the timing of a normal memory access.

Abstract: A method and apparatus for storing data in a memory device is described. The apparatus is configured to perform the following steps. The method employs a two-step technique which allows the out-of-order completion of read and write operations. When a write operation requires a resource needed for the completion of a read operation, the data being written is stored in a write data buffer in the memory device. The write data is stored in the buffer until a datapath is available to communicate the data to the memory device's memory core. Once the resource is free (or the memory device, or its controller force the write to complete) the data is written to the memory core of the memory device using the now-free datapath.

Abstract: An apparatus and method for concurrently refreshing first and second rows of memory cells in a dynamic random access memory (DRAM) component that includes a plurality of banks of memory cells organized in rows. A command interface in the DRAM component receives activate requests and precharge requests. A row register in the DRAM component indicates a row in the DRAM component. Logic in the DRAM component activates the row indicated by the row register in response to an activate request and precharges the row in response to a precharge request, the row being in a bank indicated by the activate request and by the precharge request.

Abstract: A method for reducing the communication overhead over the interface bus to the memory devices for refresh operations. This is done by refreshing multiple banks in response to a single command. Multibank refresh is made possible by varying the current profile for the row sense and row precharge currents during a refresh operation, as compared to normal memory access. Unlike normal memory accesses, data is not needed, and a fast access time is not required. This allows the current to be spread using different circuitry for driving the current to lessen current spikes. The spread current is still maintained within the timing of a normal memory access.

Abstract: A memory system includes a set of memory devices. An interconnect structure links the set of memory devices to one another. A memory controller is connected to the interconnect structure. The memory controller is configured to apply a control signal to the interconnect structure such that a specified subset of the set of memory devices performs a refresh operation.

Abstract: A method and apparatus for initializing dynamic random access memory (DRAM) devices is provided wherein a channel is levelized by determining the response time of each of a number of DRAM devices coupled to a bus. Determining the response time for a DRAM device comprises writing logic ones to a memory location of the DRAM device using the bus. Subsequently, a read command is issued over the bus, wherein the read command is addressed to the newly-written memory location of the DRAM device. The memory controller then measures the elapsed time between the issuance of the read command and the receipt of the logic ones from the DRAM device, and this elapsed time is the response time of the DRAM device. Following the determination of a response time for each DRAM device, and using the longest response time, a delay is computed for each of the DRAM devices coupled to the bus so that the response time, in clock cycles, of each of the DRAM devices coupled to the bus equals the longest response time.

Abstract: A memory device includes an interconnect with control pins and bidirectional data pins. A memory core stores data. A memory interface circuit is connected to the interconnect and the memory core. The memory interface circuit includes a delay circuit to establish a write delay during a memory core write transaction such that the memory core write transaction has a processing time that is substantially equivalent to a memory core read transaction. The delay circuit delays the memory core write transaction for a time corresponding to the time required for signals to travel on the interconnect.

Abstract: A method for reducing the communication overhead over the interface bus to the memory devices for refresh operations. This is done by refreshing multiple banks in response to a single command. Multibank refresh is made possible by varying the current profile for the row sense and row precharge currents during a refresh operation, as compared to normal memory access. Unlike normal memory accesses, data is not needed, and a fast access time is not required. This allows the current to be spread using different circuitry for driving the current to lessen current spikes. The spread current is still maintained within the timing of a normal memory access.