©2010 Silicon Storage Technology, Inc.

S71409-01-000

01/10

7

1.8V Serial Quad I/O (SQI) Flash Memory

SST26WF032

Advance Information

Device Protection

The SST26WF032 has a Block-Protection register which provides a software mechanism to write-lock

the array and write-lock, and/or read-lock, the parameter blocks. The Block-Protection Register is 80

bits wide per device: two bits each for the eight 8 KByte parameter blocks (write-lock and read-lock),

and one bit each for the remaining 32 KByte and 64 KByte overlay blocks (write-lock). See Table 8 for

address range protected per register bit.

Each bit in the Block-Protection Register can be written to a ‘1’ (protected) or ‘0’ (unprotected). For the

parameter blocks, the most significant bit is for read-lock, and the least significant bit is for write-lock. Read-

locking the parameter blocks provides additional security for sensitive data after retrieval (e.g., after initial

boot). If a block is read-locked all reads to the block return data 00H. All blocks are write-locked and read-

unlocked after power-up. The Write Block Locking Register command is a two cycle command requiring

Write-Enable (WREN) to be executed prior to the Write Block-Protection Register command.

Figure 6: Block Locking Memory Map

1409 F40.0

Top of Memory Block

8 KByte

8 KByte

8 KByte

8 KByte

32 KByte

64 KByte

64 KByte

64 KByte

32 KByte

8 KByte

8 KByte

8 KByte

8 KByte

Read Lock

Write Lock

Read Lock

Write Lock

Write Lock

Bottom of Memory Block