Methods and systems are provided for improved protection of radio frequency identification tag memory by using two or more "brownout-safe" pointer registers (instead of a single pointer register) that are logically concatenated to form a complete address for the boundary between a locked portion and an unlocked portion of the tag memory. A first pointer is a coarse pointer identifying a block of memory containing the boundary. A second pointer is a fine pointer identifying a specific location within the identified coarse block of memory. The coarse pointer may be a gray-coded or linear pointer. Similarly, the fine pointer may be a gray-coded or linear pointer.