Signature

Documents signature bytes used on EPROM, AT89C51, 87C51, etc.

TODO:

 * Is 87C51 and 89C51 signature protocol the same?
 * Do mcs51 mask ROM parts support signature?
 * Are EPROM signatures compatible with mcs51 signatures?

JEDEC

https://www.jedec.org/standards-documents/docs/jep-106ab

Think these are flash specific

"JEDEC SOLID STATE TECHNOLOGY ASSOCIATION"

"The intent of this identification code is that it may be used whenever a digital field is required, e.g., hardware, software, documentation, etc."

89C51 family

IDs are found at special NV memory address 0x30-0x32

Sig (hex)	Vendor	Chip label	Die ID	Notes
1E51FF	Atmel	AT89C51	19052
9ED100	Atmel	AT89C51	19651
1E52FF	Atmel	AT89C52	(19652)	Die ID was for a AT89C52, but not verified to have the same signature words