WRERRF=B_0x0, KEYVALID=B_0x0, RDERRF=B_0x0, BUSY=B_0x0
SAES status register
| RDERRF | Read error flag This bit is set when an unexpected read to the SAES_DOUTR register occurred. When set RDERRF bit has no impact on the SAES operations. This flag is cleared by setting the RWEIF bit in SAES_ICR register. If RWEIE bit is set in SAES_IER register an interrupt is generated when RDERRF is set. It is cleared by setting the RWEIF bit of the SAES_ICR register. 0 (B_0x0): No error 1 (B_0x1): Unexpected read to SAES_DOUTR register occurred during computation or data input phase. |
| WRERRF | Write error flag This bit is set when an unexpected write to the SAES_DINR register occurred. When set WRERRF bit has no impact on the SAES operations. This flag is cleared by setting the RWEIF bit in SAES_ICR register. If RWEIE bit is set in SAES_IER register an interrupt is generated when WRERRF is set. It is cleared by setting the RWEIF bit of the SAES_ICR register. 0 (B_0x0): No error 1 (B_0x1): Unexpected write to SAES_DINR register occurred during computation or data output phase. |
| BUSY | Busy This flag indicates whether SAES is idle or busy. SAES is flagged as idle when disabled or when the last processing is completed. SAES is flagged as busy when processing a block data, preparing a key (ECB or CBC decryption only), fetching random number from the RNG, or transferring a shared key to target peripheral. When GCM encryption is selected, this flag must be at zero before suspending current process to manage a higher-priority message. BUSY must also be cleared before selecting the GCM final phase. 0 (B_0x0): Idle 1 (B_0x1): Busy |
| KEYVALID | Key valid flag This bit is set by hardware when the key of size defined by KEYSIZE is loaded in SAES_KEYRx key registers. The EN bit can only be set when KEYVALID is set. In normal mode when KEYSEL[2:0] is at 000, the key must be written in the key registers in the correct sequence, otherwise the KEIF flag is set and KEYVALID remains cleared. When KEYSEL[2:0] is different from zero, the BUSY flag is automatically set by SAES. When the key is loaded successfully, BUSY is cleared and KEYVALID set. Upon an error, KEIF is set, BUSY cleared and KEYVALID remains cleared. If set, KEIF must be cleared through the SAES_ICR register, otherwise KEYVALID cannot be set. See the KEIF flag description for more details. For further information on key loading, refer to Section23.4.18: SAES key registers. 0 (B_0x0): Key not valid 1 (B_0x1): Key valid |