P89V51RB can not set security bit with serial number

[nova]

  Hi all,
  I am Nova, I have done very much with P89V51, and I meet a problem with P89V51RB now.
I have two kind of P89V51RB, one 's label is white and one 's is yellow white. The White is very good, but the Yellow have some problem:
- First, one year before, We could not erase chip normaly but we must used Erase Flash Page to erase chip.
- Second, with the White, I can protect my program easily by choosing: Program Security Bit with Serial Number Setting. But with the Yellow label, I can not do that. Because after I do that, I still choose Display Memory and read the program easily.

[Andy Ayre]

The erase problem should be solved with the latest bootloader, which you can get from the resources page of the Flash Magic website.

As for the serial number problem try also using the latest bootloader and post back if the problem is solved or not.

Andy