Battery-Backed RAM

Zynq UltraScale+ Device Technical Reference Manual (UG1085)

Document ID
Release Date
2.4 English

The BBRAM module is one of the available options for storing the device AES key. The BBRAM is a static RAM array. When the device has power on the PS_VCCAUX supply, the BBRAM is powered by the PS_VCCAUX supply. When the PS_VCCAUX supply is switched off, the device automatically switches the BBRAM power over to PS_VCCBATT. The key stored in BBRAM can only be stored in its unencrypted form (i.e., red). It cannot be obfuscated (family) or encrypted (black). The BBRAM can also be cleared, which is valuable as a tamper response.