Digital ICs/DSP: 18-Mbit Dual-Port RAMs Offer Synchronous Or Asynchronous Ports

Available with either an asynchronous or synchronous interface, the industry's first 18-Mbit dual-port RAMs come in a 512-kword by 36-bit configuration. The availability of both interfaces allows designers to select the one better suited for their system. The synchronous IDT 70T3539M operates at 166 MHz, and access times for the asynchronous 70T653M drop to as low as 10 ns, making both suitable for telecommunications, datacommunications, and networking applications. The 70T3539M includes full-boundary counters, multiple independent chip and byte enables, a collision-detect signal, and synchronous interrupts. The asynchronous version has "busy" logic, semaphore flags, interrupts, and a RapidWrite mode. Both dual-port RAMs come in small-footprint 256-contact BGA packages and sell for $110 each in lots of 10,000 units.