The EM639165 SDRAM is a high-speed CMOS synchronous DRAM containing 128 Mbits. It is internally configured as 4 Banks of 2M word x 16 DRAM with a synchronous interface (all signals are registered on the positive edge of the clock signal, CLK). Read and write accesses to the SDRAM are burst oriented; accesses start at a selected location and continue for a programmed number of locations in a programmed sequence. Accesses begin with the registration of a Bank Activate command which is then followed by a Read or Write command.
The EM639165 provides for programmable Read or Write burst lengths of 1, 2, 4, 8, or full page, with a burst termination option. An auto precharge function may be enabled to provide a self-timed row precharge that is initiated at the end of the burst sequence. The refresh functions, either Auto or Self Refresh are easy to use.
By having a programmable mode register, the system can choose the most suitable modes to maximize its performance. These devices are well suited for applications requiring high memory bandwidth and particularly well suited to high performance PC applications.