SM CODE
FSMC_SM_1
Detailed implementation
If FSMC interface is used to connect an external memory where safety-relevant data are
stored, information redundancy techniques for stored data are able to address faults affecting
the FSMC interface. The possible techniques are:
•
using redundant copies of safety-relevant data and performing coherence check before
consuming
•
organizing data in arrays and computing the checksum field to check before use
Error reporting
Depends on implementation
Fault detection time
Depends on implementation
Addressed fault model
Permanent/transient
Dependency on
Device
configuration
FSMC interface is available only on selected part numbers.
Initialization
Depends on implementation
Periodicity
On demand
Test for the diagnostic
Not applicable
Multiple-fault protection
CPU_SM_0: Periodic core self-test software
Recommendations and known limitations
This mechanism must be used just if FSMC external memory is used to store safety-related
data.
This safety mechanism can overlap with information redundancy techniques implemented at
system level to address failure of physical device connected to FSMC port.
Table 67.
FSMC_SM_2
SM CODE
FSMC_SM_2
Description
Periodic read-back of FSMC configuration registers
Ownership
End user
Detailed implementation
This method must be applied to FSMC configuration registers.
Detailed information on the implementation of this method can be found in
Section 3.6.14 Extended interrupt and events controller (EXTI)
.
Error reporting
Refer to NVIC_SM_0
Fault detection time
Refer to NVIC_SM_0
Addressed fault model
Refer to NVIC_SM_0
Dependency on
Device
configuration
FSMC interface is available only on selected part numbers.
Initialization
Refer to NVIC_SM_0
Periodicity
Refer to NVIC_SM_0
Test for the diagnostic
Refer to NVIC_SM_0
Multiple-fault protection
Refer to NVIC_SM_0
Recommendations and known limitations
Refer to NVIC_SM_0
Table 68.
FSMC_SM_3
SM CODE
FSMC_SM_3
Description
ECC engine on NAND interface in FSMC module
Ownership
ST
Detailed implementation
The FMC NAND Card controller includes two error correction code computation hardware
blocks, one per memory bank. They reduce the host CPU workload when processing the ECC
by software.
ECC mechanism protects data integrity on the external memory connected to NAND port.
UM2305
Hardware and software diagnostics
UM2305
-
Rev 10
page 43/110
