Meinberg DCF77 UA509 - Manual (Page 13)

13
Firmware Updates
Whenever the on-board software must be upgraded or modified, the new firmware can
be downloaded to the internal flash memory via the serial port COM0.
If the pin "Boot" of the rear connector (see table Rear Connector Pin Assignments)
is pulled down to ground while the system is powered up, a bootstrap-loader will be
activated that waits for instructions from the serial port COM0. The new firmware can
be sent to the UA509 from any standard PC with serial interface. A loader program
will be shipped together with the file containing the image of the new firmware.
The contents of the program memory will not be modified until the loader program
has sent the command to erase the flash memory. So if the "Boot" signal is grounded
unintentionally while the system is powered up, the firmware will not be changed
accidentially. After the next power-up, the system will be ready to operate again.
Inquiring Serial Number and Software Revision
The serial number and the revision of the loaded software can be red out by sending
the three characters "
SN! " via COM0 to the clock that starts sending the following
string:
SN:UA509 9041260 REV:03.00/01
The software revision is updated automatically with every update of the firmware. The
serial number is fixed in an I
2 C bus EEPROM and can not be changed.