SmartFusion Customizable System-on-Chip (cSoC)
Revision 10 1-3
devices from the PCB design. Flash-based SmartFusion cSoCs simplify total system design and reduce
cost and design risk, while increasing system reliability.
Immunity to Firm Errors
Firm errors occur most commonly when high-energy neutrons, generated in the atmosphere, strike a
configuration cell of an SRAM FPGA. The energy of the collision can change the state of the
configuration cell and thus change the logic, routing, or I/O configuration behavior in an unpredictable
way.
Another source of radiation-induced firm errors is alpha particles. For alpha radiation to cause a soft or
firm error, its source must be in very close proximity to the affected circuit. The alpha source must be in
the package molding compound or in the die itself. While low-alpha molding compounds are being used
increasingly, this helps reduce but does not entirely eliminate alpha-induced firm errors.
Firm errors are impossible to prevent in SRAM FPGAs. The consequence of this type of error can be a
complete system failure. Firm errors do not occur in SmartFusion cSoCs. Once it is programmed, the
flash cell configuration element of SmartFusion cSoCs cannot be altered by high energy neutrons and is
therefore immune to errors from them. Recoverable (or soft) errors occur in the user data SRAMs of all
FPGA devices. These can easily be mitigated by using error detection and correction (EDAC) circuitry
built into the FPGA fabric.
Specifying I/O States During Programming
You can modify the I/O states during programming in FlashPro. In FlashPro, this feature is supported for
PDB files generated from Designer v8.5 or greater. See the FlashPro User’s Guide for more information.
Note: PDB files generated from Designer v8.1 to Designer v8.4 (including all service packs) have
limited display of Pin Numbers only.
The I/Os are controlled by the JTAG Boundary Scan register during programming, except for the analog
pins (AC, AT and AV). The Boundary Scan register of the AG pin can be used to enable/disable the gate
driver in software v9.0.
1. Load a PDB from the FlashPro GUI. You must have a PDB loaded to modify the I/O states during
programming.
2. From the FlashPro GUI, click PDB Configuration. A FlashPoint – Programming File Generator
window appears.
3. Click the Specify I/O States During Programming button to display the Specify I/O States During
Programming dialog box.
4. Sort the pins as desired by clicking any of the column headers to sort the entries by that header.
Select the I/Os you wish to modify (Figure 1-1 on page 1-4).
5. Set the I/O Output State. You can set Basic I/O settings if you want to use the default I/O settings
for your pins, or use Custom I/O settings to customize the settings for each pin. Basic I/O state
settings:
1 – I/O is set to drive out logic High
0 – I/O is set to drive out logic Low
Last Known State – I/O is set to the last value that was driven out prior to entering the
programming mode, and then held at that value during programming
Z -Tri-State: I/O is tristated
