MEN BL51E, Руководство пользователя

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Getting Started
20BL51E00 E2

2020-03-27 Page 40
2.9.2 Accessing SMBus/I2C Devices using Standard Linux I2C Tools
For detailed information how to access SMBus/I2C devices using standard Linux I2C
tools:
2.9.3 Managing RTC Time Adjustments
During the boot process, the CPU firmware gets the time from the system RTC (ERTC)
and sets the CRTC (Chipset Real-Time Clock) accordingly. In the next step, the operating
system (OS) gets the time from the CRTC and sets the system time accordingly. Now the
OS system time is updated independently of the CRTC via periodic clock interrupts. Thus,
over time (i.e. as the system runs), the system time may become out of sync with the
CRTC/ERTC time.
If the system time is adjusted (e.g. by the user), the ERTC time will not be automatically
adjusted by the time management, because the OS is not aware of the additional ERTC.
The ERTC time will not be updated and is out of date. During the next system boot, the
OS would use the outdated time.
MEN provides a dedicated ERTC driver to manage system time adjustments.
2.9.4 Setting the UART Modes of BL51E Interfaces
MEN provides a Linux tool that allows to switch the UART modes of legacy serial I/O
interfaces.
The Linux tool supports the following BL51E interfaces (front panel designations):
 X11

X12
See the MEN website for application note Using the Standard I2C Tools on
MEN CPUs under Linux .
More information on supported functions and hardware implementation
 See Chapter 4.1 SMBus/I2C Devices on page 54 .
See the MEN website for application note Using the System RTC (ERTC) on
MEN CPUs under Linux .
See the MEN website for more information and documentation:
www.men.de/software/13sc24-91/