Little Board™/486e Technical Manual
Battery-Backed Clock
An AT-compatible battery-backed real-time clock (with CMOS RAM) is standard on the
Little Board/486e CPU. A 3.6-volt Lithium battery connected to the Utility Connector, J16, can power the clock. Battery drain for the clock is less than 1 uA. This battery will support the clock for about 10 years.
Use the Ampro SETUP utility to set the current time and date in the real-time clock, as well as SETUP information in the CMOS RAM portion of the clock chip (configuration memory).
The contents of the configuration memory are also stored in an onboard EEPROM. The ROM BIOS reads the EEPROM to get configuration information if the CMOS RAM data is lost. This means that the board functions without the battery. However, without a battery the real-time clock date and time will not be correct.
