3 Volt Intel® Advanced+ Boot Block Flash Memory Stacked-CSP Family
3.7.1
Block Locking Operation Summary
The following concisely summarizes the locking functionality.
All blocks are locked when powered-up, and can be unlocked or locked with the Unlock and Lock
commands.
• The Lock-Down command locks a block and prevents it from being unlocked when WP# = 0.
• When WP# = 1, Lock-Down is overridden and commands can unlock/lock locked-down
blocks.
• When WP# returns to 0, locked-down blocks return to Lock-Down.
• Lock-Down is cleared only when the device is reset or powered-down.
The locking status of each block can set to Locked, Unlocked, and Lock-Down, each of which will
be described in the following sections. A comprehensive state table for the locking functions is
shown in Table 8 on page 21, and a flowchart for locking operations is shown in Figure 19 on
page 50.
3.7.2
Locked State
The default status of all blocks upon power-up or reset is locked (states [001] or [101]). Locked
blocks are fully protected from alteration. Any program or erase operations attempted on a locked
block will return an error on bit SR.1 of the status register. The status of a locked block can be
changed to Unlocked or Lock-Down using the appropriate software commands. Unlocked blocks
can be locked issuing the “Lock” command sequence, 60h followed by 01h.
3.7.3
3.7.4
Unlocked State
Unlocked blocks (states [000], [100], [110]) can be programmed or erased. All unlocked blocks
return to the Locked state when the device is reset or powered down. The status of an unlocked
block can be changed to Locked or Locked-Down using the appropriate software commands. A
Locked block can be unlocked by writing the Unlock command sequence, 60h followed by D0h.
Lock-Down State
Blocks that are Locked-Down (state [011]) are protected from program and erase operations (just
like Locked blocks), but their protection status cannot be changed using software commands alone.
A Locked or Unlocked block can be Locked-down by writing the Lock-Down command sequence,
60h followed by 2Fh. Locked-Down blocks revert to the Locked state when the device is reset or
powered down.
The Lock-Down function is dependent on the WP# input ball. When WP# = 0, blocks in Lock-
Down [011] are protected from program, erase, and lock status changes. When WP# = 1, the Lock-
Down function is disabled ([111]) and locked-down blocks can be individually unlocked by
software command to the [110] state, where they can be erased and programmed. These blocks can
then be re-locked [111] and unlocked [110] as desired while WP# remains high. When WP# goes
low, blocks that were previously locked-down return to the Lock-Down state [011] regardless of
any changes made while WP# was high. Device reset or power-down resets all blocks, including
those in Lock-Down, to Locked state.
Datasheet
19
INTEL [ INTEL ]
