THE M41ST85MX6 from STMicroelectronics is an SO28 device, available from Braemac , that combines XTAL, serial RTC with uP and NVRAM supervisory functions.
By integrating the XTAL better accuracy can be provided and reduces the risk of tampering.
At the heart of the M41ST85MX6 is the programmable, battery-backed RTC section which can be accessed via a 400kHz I2C interface.
The M41ST85MX6's microprocessor supervisor section includes an early power-fail warning circuit, with a 1.25V reference, and a robust reset circuit, which can be triggered by multiple sources (including two reset input pins and a power-on reset/low-voltage detect circuit). To find out more contact Braemac.