Artesyn COMX-P2020 Installation and Use (February 2015) - Manual (Page 80)

Functional Description
COMX-P2020 Module Installation and Use (6806800K97E) 80
4.5.4 DDR3 SPD
The DDR3 SOUDIMM connects I2C#2 with the address: 0xA6h, 0x66h, 0x36h. For COMX-
P2020 just support booting from MicroSD Card or SPI Flash, the memory controller must be
initialized before COMX-P2020 copies the U-boot image from the media to memory and jump
to the U-boot start entry.
4.5.5 RTC and Watchdog Timer
The M41ST85WMX6TR has an internal quartz-controlled oscillator with a frequency of 32.768
kHz and error not exceeding +/-35 ppm, which equates to +/-1.53 minutes per month. The
internal circuit can be set to get a precision of +/-2ppm (please refer to datasheet for details),
which equates to +/-5.25 seconds per month.
M41ST85WMX6TR contains the century, year, month, date, day, hour, minutes, second, and
tenths/hundredths of a second in a 24-hour BCD format.
M41ST85WMX6TR contains an internal watchdog. The watchdog can be fed through the I2C
or WDI pin. The watchdog is turned off by default.
4.6 Reset Logic
M41ST85WMX6TR will pull H_RESET# low when the VCC is below Vpfd=2.6V, thus realizing
the power fail reset function and power-on reset.