M58PR256J datasheet(36/114 Pages) STMICROELECTRONICS

No. de pieza	M58PR256J

Descripción Electrónicos	256 Mbit or 512 Mbit (x16, Multiple Bank, Multilevel, Burst) 1.8 V supply Flash memories

PDF	114 Pages

Scroll/Zoom	100%

Fabricante Electrónico	STMICROELECTRONICS [STMicroelectronics]

Página de inicio	http://www.st.com

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36 / 114 page

Command interface

M58PR256J, M58PR512J

36/114

4.29

Lock-Down EFA Block command

The Lock-Down EFA Block command is used to lock down a locked or unlocked EFA Block.

A locked-down EFA Block cannot be programmed or erased. The lock status of a locked-

down EFA Block cannot be changed when WP is low, VIL. When WP is High, VIH, the lock-

down function is disabled and the locked EFA Blocks can be individually unlocked by issuing

the Unlock EFA Block command.

Two Bus Write cycles are required to issue the Lock-Down EFA Block command.

●

The first bus cycle sets up the Lock-Down EFA Block command.

●

The second Bus Write cycle latches the Block address and locks down the Block.

The lock status can be monitored for each EFA Block using the Read Electronic Signature

command.

Locked-Down EFA Blocks revert to the locked (and not locked-down) state when the device

is reset on power-down. Table 21 shows the Lock Status after issuing a Lock-Down EFA

Block command.

Refer to Section 12: Block locking for a detailed explanation and to Appendix C, Figure 25:

Main Array and EFA locking operations flowchart and pseudo code, for a flowchart for using

the Lock-Down EFA Block command.

M58PR256J Datasheet(PDF) 36 Page - STMicroelectronics