Table 28-5. Interface Signals (continued)
Signal Width From To Description
sacc 64 or 32 FMU Platform Direct sacc (supervisor access control) register
numsg 8 FMU Platform NUMSG bit field - Binary encoded number of segments
0x40 for 64 segments
0x20 for 32 segments
fac_enable 1 SIM FMU SIM Option bit - derived from an IFR bit and captured in
SIM_SOPTx. A way to disable the flash access control for phantom
devices without this feature.
fac_enable==1 - Access Control feature is enabled
fac_enable==0 - Access Control feature is disabled
• During the reset sequence, XACC registers are written to all
"1"s.
• During the reset sequence, SACC registers are written to all
1"s.
• Implied protection based on XACC registers is turned off.
28.5.4.2.2 Flash Command Impact
Program Longword/Phrase/
Section
If the targeted flash location is in an execute-only protected segment, then these program
commands are not allowed unless a Read 1s All Blocks command is executed and returns
with a pass code (which means the part has been fully erased). After the Read 1s All Blocks
command is executed with a pass code returned, then the protected segment is open to
program commands. To close off programmability to execute-only spaces once again, the
device must be reset or a Read 1s All Blocks command is executed with a fail result.
Attempts to program in a protected segment when not open to program commands causes a
Protection Violation flag.
PGMCHK
The FMU will not execute the PGMCHK command on a segment that has been configured as
execute-only. The Flash Protection Violation flag is set if an attempt is made to execute
PGMCHK command on an execute-only address.
Erase Flash Sector
If the targeted flash sector is in an execute-only protected segment, then the Erase Flash
Sector command is not allowed, and sets the Protection Violation flag. The only means of
erasing protected space is by an Erase All operation.
ERSALL
The Erase All Blocks command is not affected by Access Control. An Erase All Blocks
command will erase any libraries that have been programmed in any execute-only segment.
The programmed execute-only assignment is not erased as part of the Erase All Blocks
command, and access control regions remain as previously programmed.
NOTE:
The ERSALL command may be used for field upgrades. Access control states
remain programmed. Software must plan accordingly, possibly making extra space
available for future use.
ERSXA
The target regions of the command is controlled by FAC. For ERSXA, if a flash sector is in an
execute-only protected segment and it is not protected by flash protection (FPROT), it will be
erased.
RD1XA
The target regions of the command is controlled by FAC. For RD1XA, if a flash sector is in an
execute-only protected segment, it will be erase verified.
Functional description
K22F Sub-Family Reference Manual, Rev. 4, 08/2016
624 NXP Semiconductors
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