The algorithm for programming the Lock bits
is as follows (Please refer to Programming the Flash for details on Command and Data loading):
- Step A: Load Command “0010 0000”.
- Step C: Load Data Low Byte. Bit n = “0”
programs the Lock bit. If LB mode 3 is programmed (LB1 and LB2 is programmed), it is not
possible to program the Boot Lock bits by any External Programming mode.
- Give WR a
negative pulse and wait for RDY/BSY to go high.
The Lock bits can only be cleared by executing Chip Erase.