ST STM32F412 User Manual

Embedded Flash memory interface RM0402
70/1163 RM0402 Rev 6
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Figure 5 shows how to go from one RDP level to another.
Figure 5. RDP levels
3.6.4 Write protections
Up to 12 user sectors in Flash memory can be protected against unwanted write operations
due to loss of program counter contexts. When the non-write protection nWRPi bit
(0
≤ i ≤ 11) in the FLASH_OPTCR registers 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.
Table 11. Access versus read protection level
Memory area
Protection
Level
Debug features, Boot from RAM or
from System memory bootloader
Booting from Flash memory
Read Write Erase Read Write Erase
Main Flash Memory
Level 1 NO NO
(1)
YES
Level 2 NO YES
Option Bytes
Level 1 YES YES
Level 2 NO NO
OTP
Level 1 NO NA YES NA
Level 2 NO NA YES NA
1. The main Flash memory is only erased when the RDP changes from level 1 to 0. The OTP area remains unchanged.
Level 1
0 leveL2 leveL
hAA = PDRhCC = PDR
RDP /= AAh
RDP /= CCh
default
Options write (RDP level increase) includes
- Options erase
- New options program
Options write (RDP level decrease) includes
- Mass erase
- Options erase
- New options program
Options write (RDP level identical) includes
- Options erase
- New options program
RDP = AAh
Others option(s) modified
RDP /= AAh & /= CCh
Others options modified
Write options
including
RDP = AAh
Write options
including
RDP = CCh
Write options
including
RDP = CCh
Write optionsincluding
RDP /= CCh & /= AAh
ai16045

ST STM32F412 Specifications

General

Brand	ST
Model	STM32F412
Category	Microcontrollers
Language	English