| Flash memory (sometimes called "flash RAM")
is a type of constantly-powered nonvolatile memory that can be erased and
reprogrammed in units of memory called blocks. It is a variation of electrically
erasable programmable read-only memory (EEPROM) which, unlike flash memory,
is erased and rewritten at the byte level, which is slower than flash memory
updating. Flash memory is often used to hold control code such as the basic
input/output system (BIOS) in a personal computer. When BIOS needs to be
changed (rewritten), the flash memory can be written to in block (rather
than byte) sizes, making it easy to update. On the other hand, flash memory
is not useful as random access memory (RAM) because RAM needs to be addressable
at the byte (not the block) level. |
