Program Memory

In a computer system, the program memory is the memory storing the program. Since it contains the program (typically a list of instructions for the CPU), it is read-only, in contrast to data memory, which needs to be writeable. In embedded systems, program memory is either ROM or (in most cases) flash memory. On large systems (such as PCs, servers, tablets, etc., which typically have gigabytes of memory), the programs (applications) are all loaded into RAM. Program memory (ROM) is only needed for the actual boot process of the computer, right after a reset release.