33.7.11 Programming the Lock Bits

The algorithm for programming the Lock bits is as follows (Please refer to Programming the Flash for details on Command and Data loading):

  1. Step A: Load Command “0010 0000”.
  2. 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.
  3. Give WR a negative pulse and wait for RDY/BSY to go high.

The Lock bits can only be cleared by executing Chip Erase.