Here’s an application note from Microchip: Debugging stand-alone real-time clock/calendar-based applications (PDF!)
An increasing number of applications require Real-Time
Clock/Calendar (RTCC) devices.
Microchip’s RTCC’s (I2C™ and SPI) are feature-rich
devices that incorporate EEPROM, Time/Date
registers, Time-Stamp registers, alarm modules,
SRAM, a watchdog timer, and event detect modules,
making them useful in many timekeeping applications.
This application note describes how to debug an application using Microchip’s MCP794XX and MCP795XX RTCC devices.