A system and method for performing data transfers within a computer system is provided. The system includes a controller configured to dynamically adjust the interleave of the communications required to perform a series of data transfer operations to maximize utilization of the channel over which the communications are to be performed. The controller is able to vary the time interval between the transmission of control information that requests a data transfer and the performance of the data transfer by signaling the beginning of the data transfer with a strobe signal sent separate from the control information. The controller is able to defer the determination of how much data will be transferred in the operation by initiating the termination of a data transfer with a termination signal. The method provides a technique for distinguishing between identical control signals that are carried on the same line. The system includes a memory device with control circuitry that allows no more than one memory bank powered by any given power supply line to perform sense or precharge operations.
A timing circuit to adjust a data strobe signal received from a synchronous memory includes a delay circuit to adjustably delay the data strobe signal and to generate a delayed data strobe signal, a clock capture register to sample the delayed data strobe signal and to generate a sampled clock signal, a data capture register to sample a read data signal from the synchronous memory and to generate a sampled data signal, and an analysis circuit to determine a timing relationship between the sampled clock signal and the sampled data signal and to adjust the delay circuit based on the determined timing relationship. By way of example, the determined timing relationship may be used to delay the read data strobe signal so that it transitions (e.g., from a low state to a high state) in the middle of the data signal's data eye.
Apparatus, methods, and systems are disclosed for providing a memory device, such as a SDRAM, having distributed memory bank segments logically coupled to form a virtual memory bank. Each of the memory bank segments are proximally positioned relative to associated I/Os. In this way, the delay times from each of the memory bank segments to their respective I/Os are substantially equal to each other. In addition, the proximal positioning of the memory banks results in reduced signal delays due to reduced signal paths from each bank segment and respective I/O.
Apparatus, methods, and systems are disclosed for providing a memory device, such as a SDRAM, having distributed memory bank segments logically coupled to form a virtual memory bank. Each of the virtual memory banks has coupled to it an associated segmented sense amp which responds to an appropriate bank select signal by sensing data stored in a selected memory bank segment. The segmented sense amp uses a segmented bit line to reduce bit sense latency without decreasing bit density or increasing chip size.
A method of operating a memory device includes determining whether a read command is to be issued after a write command. A posted read command is issued before issuance of the write command. The posted read command is issued in place of the read command to be issued after the write command. The write command is issued. Next, write data is transported onto a main bus in response to the write command. Data is read from the memory device, in response to the posted read command, prior to writing the write data to the memory device. The data is stored in a buffer. The write data is transported from the main bus to the memory device to write the write data to the memory device. Then, the data is outputted from the buffer onto the main bus.
In digital signal processors serial data is passed in out and of the chip in a time division multiplexed (TDM) fashion. The TDM stream consists of many independent channels of serial data. The complexity of generating interleaved TDM serial data from multiple sources particularly in the case of multi-processor systems. This process is normally driven by a program resident on each processor. The proper sequencing of the TDM serial stream must be tested prior to making the multi-processor device ready for its application. This invention describes the use of minimal added hardware and a single output pin allowing the test and debug of program errors or device malfunctions in output serial data.