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

Is AT89C51 signature the same as P87C51 signature?

Do mcs51 mask ROM parts support signature?

Are EPROM signatures compatible with mcs51 signatures in any way?

JEDEC

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