5.1 In-Flight Reprogramming Guidance

Microchip has performed several sets of radiation tests on RT PolarFire FPGAs and determined that the FPGAs can be programmed in space, with a greater-than-99% probability of success using JTAG with DirectC.

RT PolarFire reprogramming in space is supported using JTAG with DirectC, with the following guidance:

  • Single Event Effects (SEE) Impact
    • Probability of first-time success for programming in GEO-synchronous orbit with Solar-Min conditions is calculated to be greater than 99%. If radiation disrupts programming, it is likely that the next programming attempt will be successful. Heavy ION test results can be obtained from Microchip, on request.
    • Probability of programming success in LEO is very high. No programming or verify failure was observed in accelerated ground testing. Proton test data is available from Microchip, on request.
    • In-beam reprogramming and verify is non-destructive as seen in accelerated ground testing.
    • It is unlikely that an ION will disrupt programming, since the flux in space is many orders of magnitude lower than the flux tested during accelerated ground testing.
  • Total Ionizing Dose (TID) Impact
    • No in-flight programming constraints are identified after TID testing to 100 Krad.

Auto update and IAP via SPI Flash are alternative device reprogramming options available to RT PolarFire FPGAs. For the RTPF500T devices, auto-update is available, IAP is not available when the device is configured in system controller suspend mode. These options are expected to have comparable SEE performance to JTAG with DirectC, however, they lack standalone verify capability due to system controller suspend mode enabled. This limits comprehensive checking of the programmed bitstream. If these programming options are desired, Microchip recommends using the RTPF500ZT device. The RTPF500ZT has enhanced IAP / auto update programing algorithms containing comprehensive programming checks to support in-flight reprograming. Additionally, the RTPF500ZT allows enhanced temporary exit from system controller suspend mode to support IAP. For more information, see In-Flight Reprogramming using IAP or Auto Update.