DS1381

The DS1381 is a 2K x 8 nonvolatile static RAM designed to connect directly to the port pins of a microcontroller. Eight of ten port pins required to interface with the microcontroller are reproduced by the DS1381 for general purpose use. The reproduced port pins can be both inputs and outputs and will appear exactly the same as the pins on the attached microcontroller. The static RAM is read or written with three successive cycles containing high order address, low order address and then data. Read, write and status information is passed to the DS1381 along with the high order address transfer. While transferring data to and from memory, the I/O status is locked and maintained. All data within the DS1381 is nonvolatile and data retention time is over 10 years. The DS1381 is controlled by only two signals; clock and memory select.