Real Time Clock - SMART Embedded Computing PCIE-7217 Installation And Use Manual

Functional Description
The serial console COM0 of the processor can be accessed through a USB connection
from a host computer (there is no direct serial access). For this purpose, the PCIE-7217
provides an on-board dual USB-to-Serial converter. The USB-side of this converter
connects to the host computer via the microUSB connector on the PCIE-7217 face plate.
The two serial ports of the USB-to-Serial converter each connect to one CPU's COM0 port.
When connecting a host computer to the respective microUSB port of the PCIE-7217 the
USB-to-Serial converter will become a USB device of this computer, thus providing two
serial ports (UARTs) to the host computer. A respective device driver for the USB device
needs to be installed on the host computer.
The serial console COM1 of the processor connects to the BMC on the system's
motherboard and provides Serial Over LAN (SOL) access.
The PCIE-7217 card provides one USB 2.0 host port per CPU and one USB terminal port
to access the serial console (COM port) of the card's CPUs on its face plate.
Each of the USB host ports is connected to one of two CPUs. For terminal connection, the
console USB port is available for both the CPUs.
For a Linux host to access the COM ports of the CPUs through the USB terminal port, it
needs to load the cp210x driver. The cp210x driver is available at
http://www.silabs.com/products/mcu/Pages/USBtoUARTBridgeVCPDrivers.aspx
For a Windows host to access the COM ports of the CPUs through the USB terminal port,
it needs to install the Silicon Laboratories (silabenm) Dual CP210x driver.
3.8

Real Time Clock

Each CPU on the PCIE-7217 card is provided with a battery backed up Real Time Clock
(RTC).
The RTC's battery backups on the PCIE-7217 are provided through backup capacitors.
The capacitor is capable to bridge the time needed to exchange the card between slots or
systems. The expected backup time provided by the capacitors is hours rather than days.
When installed in the MC4100, a system-level battery backup is provided to all PCIE-7217
cards through a Lithium battery, if the system is not connected to any active power input.
56 PCIE-7217 Installation and Use (6806873A01B)
Functional Description