# Reserved Flash Sectors

On RSL15, the application configuration and debug certificates are held in data flash in consecutive sectors. (Data flash in RSL15 has a sector size of 256 bytes.)

- One sector for the application configuration
- One sector for the EH_STATE debug certificate
- Ten sectors for the ROT_STATE debug certificates

Therefore, a total of 3 KB are reserved for use by the different security mechanisms.

The layout of this is shown in the "Reserved Space for Security Mechanisms" figure.

Figure: Reserved Space for Security Mechanisms

If you are not using the secure Root of Trust, then it is generally considered safe to repurpose the 10 sectors allocated to the debug certificates. The other two sectors need to be left reserved.