Hello Kotaro Hashimoto,
Concerning your question.
You refer to :
http://www.cisco.com/en/US/docs/telepresence/endpoint/software/tc5/release_notes/tc_software_release_notes_tc5.pdf
NAND Flash
The Cisco TelePresence endpoints are using a NAND flash memory for general storage and transfer of data. The endpoints running TC software will be manufactured with a new version of the flash memory. Endpoints that have the new version of the flash memory must run software TC3.1.5 and later, 4.2.3 and later or 5.1.1 and later. Some previous TC software versions will be updated to support the new flash memory. Please check the release note to find out if the new version of the flash memory is supported. If your endpoint does not have the CompatibilityLevel command it does not have the new flash memory installed. The result returned when running the command will be either 0,1 or 2: 0 = The system does not have the new flash memory installed. 1 = The system has the new flash memory installed. If downgraded, it can only be downgraded to previous TC software versions having support for the new version of the flash memory.
2 = For MX and EX: The system has the new flash memory and the new E4 sensor. Minimum software version is TC5.1.3. The support may be added to a TC4 release, please read the release notes to determine of the hardware is supported or not.
2 = For SX20: The system mainboard is Revision F or later. SX20 minimum software version is TC5.1.0.
Example: xstatus SystemUnit Hardware Module CompatibilityLevel *s SystemUnit Hardware Module CompatibilityLevel: 0 ** end
PLEASE NOTE: Due to a bug (CSCub17111.) in TC5.1.2 and TC5.1.3 the Hardware Module CompatibilityLevel is erroneously reported as 2 on EX90 when it should be 1. This makes it impossible to downgrade to software versions lower than 5.1.1. By upgrading to TC5.1.4 this error will be resolved. To downgrade an EX90 running TC5.1.2 or TC5.1.3 to earlier software version it needs to be upgraded to TC5.1.4 first to allow the downgrade.
/Hans
