PRIV=B_0x0, ENC=B_0x0, BREN=B_0x0, CTXID=B_0x0
MCE region 4 configuration register
| BREN | Base region enable BREN cannot be set if BADDRSTART > BADDREND. 0 (B_0x0): Region x is disabled. Access control of primary region (any-privilege, no encryption) applies to any access between this region start and end addresses. 1 (B_0x1): Region x is enable. Access controls and encryption option defined in this region apply to any access between this region start and end addresses. |
| CTXID | Context ID This bitfield defines the cryptographic context used by the cipher engine assigned to this region. If ENC=00 bitfield CTXID is ignored. If BREN is set write to this bitfield is ignored. If ENC=01 the key stored in MCE_CC1KEYR is used by the stream cipher. The nonce in MCE_CC1NRx registers and the version in MCE_CC1CR register are also used. If ENC=01 the key stored in MCE_CC2KEYR is used by the stream cipher. The nonce in MCE_CC2NRx registers and the version in MCE_CC2CR register are also used. 0 (B_0x0): If ENC=10 (resp. 11) the key stored in MCE_MKEYR (resp. MCE_FMKEYR) registers is used by the block cipher. If ENC=01 bypass mode is selected instead of stream cipher. 1 (B_0x1): If ENC=10 or 11 the key stored in MCE_CC1KEYR is used by the block cipher. 2 (B_0x2): If ENC=10 or 11 the key stored in MCE_CC2KEYR is used by the block cipher. 3 (B_0x3): FIELD Reserved |
| ENC | Encrypted region Those bits are taken into account only if BREN is set and if the corresponding encryption feature is available in the MCE instance (see Section 35.3: MCE implementation). Write to those bits is ignored if BREN is set. 0 (B_0x0): No effects 1 (B_0x1): Stream cipher - All allowed read (resp. write) requests are decrypted (resp. encrypted) using the stream cipher, when CCEN bit is set in MCE_CCzCFGR (where CTXID=z). 2 (B_0x2): Block cipher - All allowed read (resp. write) requests are decrypted (resp. encrypted) using the SCA resistant block cipher. If CTXID=0 and MKVALID=0 bypass mode is selected instead. If CTXID=z and CCEN bit is cleared in MCE_CCzCFGR bypass mode is also selected. 3 (B_0x3): Fast block cipher - All allowed read (resp. write) requests are decrypted (resp. encrypted) using the fast block cipher. If CTXID=0 and FMKVALID=0 bypass mode is selected instead. If CTXID=z and CCEN bit is cleared in MCE_CCzCFGR bypass mode is also selected. |
| PRIV | Privileged region This bit is taken into account only if BREN is set. 0 (B_0x0): Application can access to region x in privileged and unprivileged mode. 1 (B_0x1): Application can access to region x in privileged mode only. |