6.1 Bypass Back Level Protection Use Case
(Ask a Question)The following table lists the user case for Bypass Back Level Protection.
| Step | SPI Bitstream | Action | Result | Design Version | Design Back Level Version | Device Back Level Version |
|---|---|---|---|---|---|---|
| 1 | Golden/Recovery | Auto Programming | Pass | 2 | 1 | 1 |
| 2 | IAP/Update Bitstream | Auto Update/IAP | Pass | 3 | 2 | 2 |
| 3 | IAP/Update Bitstream | Auto Update/IAP | Fail, Attempt Programming Recovery | 4 | Not Enabled | 2 |
The steps are described as follows:
- The device programs with a bitstream version 2 and back level version 1. The current device back level version is set to 1.
- The device then updates with a bitstream version 3 and back level version 2. The current device back level version is set to 2.
- The device attempts to update itself with a bitstream version 4 and fails to update. In this case, the device attempts to recover using a golden/recovery bitstream version 2. But the recovery also fails as the current device back level protection is set to version 2 and the golden/recovery bitstream version is equal to the back level version. The Bypass Back Level Protection must be enabled (see Figure 1) for Golden/Recovery bitstream to avoid programming recovery failures because of back level protection.