Artesyn ATCA-7368 Installation and Use (June 2014) - Manual (Page 94)

Functional Description
ATCA-7368 Installation and Use (6806800M12D) 94
5.15 SMBus Connections
The following figure shows the overall SMBus connections on ATCA-7368:
The LM75 is a thermal sensor.
5.16 Real Time Clock
An external 32.768 kHz crystal sources the internal real time clock inside ICH10R with a
frequency tolerance of 20 PPM. The RTC is fully-compliant with DS1287, MC14618, PC87911
and Y2K and provides 256 bytes of backed up CMOS RAM, of which 14 bytes containing the
RTC time and date information, and RTC configuration. During power-down, the RTC
consumes 0.9uA/hr. The optional power-down backup method uses a Super CAP with a 1 Farad
capacity. This provides 300 hours of RTC/SRAM backup. The default battery is an external +3V
lithium battery with a capacity of 200mAh, which provides three years of backup.
Figure 5-5 Overall SMBus Connections