A system includes a microcomputer. The microcomputer includes a clock signal circuit, a measuring circuit, a central processing unit, and a flash memory. A user sets a frequency of a clock signal provided by the clock signal circuit. The measuring unit counts a number of cycles of the clock signal in...http://www.google.de/patents/US6006304?utm_source=gb-gplus-sharePatent US6006304 - Apparatus and method for calculating an erasure time for data stored in a flash memory
