The
X
marker in the
Perm
and
Trans
table columns indicates that the related safety mechanism is effective for
such fault model.
Table 151.
List of safety recommendations
Diagnostic
Description
Rank
Perm
Trans
Arm
®
Cortex
®
-M4
CPU_SM_0
Periodic core self-test software for Arm
®
Cortex
®
-
M4
CPU
.
++
X
-
CPU_SM_1
Control flow monitoring in
Application software
++
X
X
CPU_SM_2
Double computation in
Application software
++
-
X
CPU_SM_3
Arm
®
Cortex
®
-M4 HardFault exceptions
M
X
X
CPU_SM_4
Stack hardening for
Application software
+
X
X
CPU_SM_5
External watchdog
++
X
X
CPU_SM_6
Independent watchdog
++
X
X
CPU_SM_7
Memory protection unit (
MPU
).
++
X
X
CPU_SM_8
AMBA firewall
+
-
-
MPU_SM_0
Periodic read-back of
MPU
configuration registers
++
X
X
MPU_SM_1
MPU
software test
o
X
-
System bus architecture/BusMatrix
BUS_SM_0
Periodic software test for interconnections
++
X
-
BUS_SM_1
Information redundancy in intra-chip data exchanges
++
X
X
Embedded SRAM
RAM_SM_0
Periodic software test for static random access memory
(SRAM)
++
X
-
RAM_SM_1
Parity on SRAM2
++
X
X
RAM_SM_2
Stack hardening for
Application software
+
X
X
RAM_SM_3
Information redundancy for safety-related variables in
Application software
++
X
X
RAM_SM_4
Control flow monitoring in
Application software
X
X
RAM_SM_5
Periodic integrity test for
Application software
in RAM
X
X
RAM_SM_6
Read protection (RDP) and write protection (WRP)
+
-
-
Embedded Flash memory
FLASH_SM_0
Periodic software test for Flash memory
+
X
-
FLASH_SM_1
Control flow monitoring in
Application software
++
X
X
FLASH_SM_2
Arm
®
Cortex
®
-M4 HardFault exceptions
M
X
X
FLASH_SM_3
Option byte write protection
M
-
-
FLASH_SM_4
Static data encapsulation
+
X
X
FLASH_SM_5
Option byte redundancy with load verification
M
X
X
FLASH_SM_6
Flash memory unused area filling code
+
-
-
FLASH_SM_7
ECC on Flash memory
++
X
X
FLASH_SM_8
Read protection (RDP), write protection (WRP), and
proprietary code readout protection (PCROP)
+
-
-
UM2305
Conditions of use
UM2305
-
Rev 10
page 84/110