Precise lifetime forecasts of real industrial e.MMC

Swissbit offers the e.MMC 5.0, available in capacities from 4Gb to 64Gb, as a freely configurable MLC version EM-20 and as a preconfigured pSLC memory EM-26. The managed NAND modules for the industrial temperature range from -40 to +85°C are well suited as boot data carriers as well as for write-intensive applications.

As components that are permanently soldered via BGA, they cannot be replaced – therefore the prediction of the service life of an e.MMC is essential in helping to define the scope of an application.

The new firmware for EM-20 and EM-26 provides a very accurate counter for target, average and maximum block erases in the MLC and pSLC regions, as well as for the number of spare blocks on each chip. It also provides access via the Extended CSD Register, which is implemented as the default procedure for each e.MMC host driver.

Due to this innovation, it is possible to compare the average deletion counter with the target deletion counter after a short test phase, and to then extrapolate the results reliably. Access via the Extended CSD Register has been chosen to provide a completely standard access path, unlike implementations that use vendor-specific access patterns.

Although the e.MMC Standard supports a basic lifetime control, it shows the percentage wear of the memory only in a coarse resolution. For reliable extrapolations within the scope of the Standard, the test time is several weeks.

The lifetime forecast for a specific application profile is significantly faster and more precise thanks to the new Swissbit firmware. This makes it easier to select the capacity that is needed for the life of the application.

“We are constantly investing in the improvement of our products in order to be able to offer our customers reliable storage and embedded IoT solutions,” explained Roger Griesemer, General Manager Memory Solutions at Swissbit. “The new firmware is a big step towards effectively managing the service life of our e.MMC modules.”