STMicroelectronics STM32F405

Embedded Flash memory interface RM0090
96/1731 DocID018909 Rev 11
When a sector is readout protected (PCROP mode activated), it can only be accessed for
code fetch through ICODE Bus on Flash interface:
• Any read access performed through the D-bus triggers a RDERR flag error.
• Any program/erase operation on a PCROPed sector triggers a WRPERR flag error.
Figure 7. PCROP levels
The deactivation of the SPRMOD and/or the unprotection of PCROPed user sectors can
only occur when, at the same time, the RDP level changes from 1 to 0. If this condition is not
respected, the user option byte modification is cancelled and the write error WRPERR flag
is set. The modification of the users option bytes (BOR_LEV, RST_STDBY, ..) is allowed
since none of the active nWRPi bits is reset and SPRMOD is kept active.
Note: The active value of nWRPi bits is inverted when PCROP mode is active (SPRMOD =1).
If SPRMOD = 1 and nWRPi =1, then user sector i of bank 1, respectively bank 2 is
read/write protected (PCROP).
,EVEL
,EVEL
2$0X##
2$0X!!
2$0X##
DEFAULT
5SEROPTIONSECTORERASE
0ROGRAMNEWOPTIONS
'LOBALMASSERASE
5SEROPTIONSECTIONERASE
0ROGRAMNEWOPTIONS
7RITEOPTIONS
30-/$ACTIVE
ANDVALIDN720I
.ORESTRICTIONON
7RITEOPTIONS
7RITEOPTIONS
30-/$ACTIVE
ANDVALIDN720I
,EVEL
2$0X!!
7RITEOPTIONS
30-/$ACTIVE
ANDVALIDN720I
7RITEOPTIONS
30-/$ACTIVE
ANDVALIDN720I
7RITEOPTIONS
30-/$ACTIVE
ANDVALIDN720I
6ALIDN720IMEANSTHATNONEOFTHEN720BITSSETCANBERESETTRANSITIONFROMTO
-36