This chip provides a real time clock and a battery operated/back-upped 4096-Bit SRAM. In addition, there is a interval timer and a power-cycle counter.

In addition to the onewire interface, this chip has a 3-Wire (SPI) Interface which operates up to 2MBaud speed. When this interface is used, the 1W pin may be used as a PIO pin. The RAM is dual-ported and both the SPI interface and the Onewire interface may be used at the same time, too, which makes this chip also useful as a SPI/Onewire interface chip with internal 4096-Bit data buffer.