The PDM34078 is a 1,048,576 bit synchronous random access memory organized as 32,768 x 32 bits. This device designed with burst mode capability and interface controls to provide highperformance in second level cache designs for x86, Pentium, 680x0, and PowerPC microprocessors. Addresses, write data and all control signals except output enable are controlled through positive edgetriggered registers. Write cycles are self-timed and are also initiated by the rising edge of the clock. Controls are provided to allow burst reads and writes of up to four words in length. A 2-bit burst address counter controls the two least-significant bits of the address during burst reads and writes. The burst address counter selectively uses the 2-bit counting scheme required by the x86 and Pentium or 680x0 and PowerPC microprocessors as controlled by the mode pin. Individual write strobes provide byte write for the four 8-bit bytes of data. An asynchronous output enable simplifies interface to high-speed buses. |