Serial Quad I/O (SQI) Flash Memory
SST26VF016 / SST26VF032
Data Sheet
Device Protection
The SST26VF016/032 have 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
48/80 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
Tables 8 - 9 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 or reset. 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.
Top of Memory Block
8 KByte
Read Lock
Write Lock
8 KByte
8 KByte
8 KByte
32 KByte
64 KByte
Write Lock
64 KByte
64 KByte
32 KByte
8 KByte
Read Lock
Write Lock
8 KByte
8 KByte
8 KByte
Bottom of Memory Block
1359 F40.2
Figure 6:
Block Locking Memory Map
©2010 Silicon Storage Technology, Inc.
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06/10
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