A read only memory (ROM) is a memory device designed to hold information (program, data) in a permanent or semipermanent way - ROMs are non-volatile. They keep their data when power is removed.
PCs use ROMS to store the boot-up program and other routines (BIOS), and the SBC5206 microcomputer uses ROM to store its dBug monitor operating system.
Conceptually, a ROM is an addressed array of registers. Figure 124
shows a simple
ROM. The 2 address lines are used to address the 4 memory
locations.
ROM technology has developed over the years and a variety of ROMs are available.
The SBC5206 microcomputer system has 256KB of flash ROM (to stored the dBug monitor).
This consists of two
flash ROM chips, in the address range
$FFE0 0000 to $FFE3 FFFF.
ANU Engineering - ENGN3213