Embedded Software for SoC - Grupo de Mecatrônica EESC/USP

Detecting Soft Errors by a Purely Software Approach 45
3. EXPERIMENTAL RESULTS
In order to evaluate both the feasibility and the effectiveness of the proposed
approach‚ we selected a C program to be used as a benchmark. We then applied
the detection approach by means of C2C translator‚ to get the hardened version
of the target program. Finally‚ we performed a set of fault injection experiments
and radiation ground testing on the original program as well as in the
modified version‚ aiming at comparing the two program’s behaviors.
During fault injection experiments‚ single bit flips were injected in memory
areas containing the program’s code‚ data segment and the internal processor’s
registers by software simulation [10] using a commercially available tool:
the d3sim simulator [11]. To achieve this‚ the generic command file was
generated (see Figure 4-6).
Command (1) tells to d3sim the condition when t (state machine counter)
will be greater than INSTANT (the desired fault injection instant). When
this condition is true‚ the execution of the program in progress is suspended‚
the XOR operation between TARG (the chosen SEU-target corresponding to
the selected register or memory byte) and an appropriate binary mask
(XOR-VALUE) is achieved‚ prior resuming main program execution. TARG
symbolizes a memory location or a register. XOR_VALUE specifies the
targeted bit.
Command (2) sets a breakpoint at the end of the program. When the
program counter reaches there‚ the simulator will print the memory segment