Flash memory interface

PM0059

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DocID15687 Rev 5

Figure 3. RDP levels

2.6.4

Write protections

The user sectors (0 to 11) in Flash memory can be protected against unwanted write

operations due to loss of program counter contexts. When the not write protection bit in

sector i (nWRPi, 0

≤ i ≤ 11) is low, the corresponding sector cannot be erased or

programmed. Consequently, a mass erase cannot be performed if one of the sectors is

write-protected.

If an erase/program operation to a write-protected part of the Flash memory is attempted

(sector protected by write protection bit, OTP part locked or part of the Flash memory that

can never be written like the ICP), the write protection error flag (WRPERR) is set in the

FLASH_SR register.

Note:

When the memory read protection level is selected (RDP level = 1), it is not possible to

program or erase Flash memory sector i if the CPU debug features are connected (JTAG or

single wire) or boot code is being executed from RAM, even if nWRPi = 1.