Mask ROM
From Free net encyclopedia
Mask ROM refers to a kind of ROM (read-only memory) whose contents are programmed by the IC manufacturer. In other words, it is not a user-programmable ROM. The terminology mask is used in IC fabrication.
Since the process is costly, mask ROM is used when the needed volume is high and it is absolutely certain that the contents will not change.
It is common practice to use UV-EPROM for the development phase of a project, and only after the code/data have been finalized is mask ROM ordered.
The main advantage of mask ROM is its cost, since it is significantly cheaper than other kinds of ROM, but if an error in the data/code is found, the entire batch must be thrown away.