M25PE80 Datasheet, PDF (38/66 Pages) STMicroelectronics – 8 Mbit, low-voltage, Page-Erasable Serial Flash memory with Byte alterability, 50MHz SPI bus, standard pinout

Instructions
M25PE80
Table 13. Not for new design: lock registers for the M25PE80 in T7Y process⁽¹⁾
Sector
Bit
Value
All sectors in T9HX process
All sectors except for sector 0
and sector 15 in T7Y process
Sector 0, sector 15 in T7Y
process
b7-b2
‘0’
b1 Sector lock down bit value (refer to Table 11)
b0 Sector write lock bit value (refer to Table 11)
‘1’
Only b3 and b2 are taken into account to modify
the subsector write lock and lock down bits⁽²⁾
b7
‘0’
Only b1 and b0 are taken into account to modify
the sector write lock and lock down bits⁽³⁾
b3 Subsector lock down bit value (refer to Table 11)
b2 Subsector write lock bit value (refer to Table 11)
b1 Sector lock down bit value (refer to Table 11)
b0 Sector write lock bit value (refer to Table 11)
1. The table rows in gray are true for products processed in the T7Y process only.
2. b6-b4 and b1-b0 must be reset to ‘0’.
3. b6-b2 must be reset to ‘0’.
For products processed in the T7Y process only (see Important note on
page 6):
Protection always prevails:
● When the lock down bit of sector 0 or sector 15 is set to ‘1’.
– If the lock down bit of sector 0 is ‘1’, all the lock down bits of the subsectors in
sector 0 are forced to ‘1’.
– If the lock down bit of sector 15 is ‘1’, all the lock down bits of the subsectors in
sector 15 are forced to ‘1’
● When the write lock bit of sector 0 or sector 15 is set to ‘1’.
– if the write lock bit of sector 0 is ‘1’, the write lock bits of all the subsectors in sector
0 are forced to ‘1’ (even if their lock down bits are set to ‘1’).
– if the write lock bit of sector 15 is ‘1’, the write lock bits of all the subsectors in
sector 15 are forced to ‘1’ (even if their lock down bits are set to ‘1’).
● When the write lock bit of sector 0 or sector 15 is reset to ‘0’.
– if the write lock bit of sector 0 is ‘0’, all the subsectors in sector 0 whose lock down
bit is ‘0’ have their write lock bits forced to ‘0’.
– if the write lock bit of sector 15 is ‘0’, all the subsectors in sector 15 whose lock
down bit is ‘0’ have their write lock bits forced to ‘0’.
● When the write lock bit of any sector or subsector is set to ‘1’, any instruction that may
modify the contents of this sector or subsector will be rejected (including sector erase
and bulk erase).
Note that when the WRLR instruction acts both on write lock (WL) and lock down (LD) bits,
it firstly programs the WL bit, and then the LD bit.
As an example, if a subsector lock register settings are xxxx0101b and a WRLR instruction
is issued with a lock register in data set to 00000010b:
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