55.5.8 TDES Key 2 Word Register y
This register can only be written if the WPEN bit is cleared in the TDES Write Protection Mode Register.
Immediately cleared on tamper detection event if TDES_MR.TAMPCLR=1.
| Name: | TDES_KEY2WRy |
| Offset: | 0x28 + y*0x04 [y=0..1] |
| Reset: | – |
| Property: | Write-only |
| Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
| KEY2W[31:24] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | – | – | – | – | – | – | – | – | |
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| KEY2W[23:16] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | – | – | – | – | – | – | – | – | |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| KEY2W[15:8] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | – | – | – | – | – | – | – | – | |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| KEY2W[7:0] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | – | – | – | – | – | – | – | – | |
Bits 31:0 – KEY2W[31:0] Key 2 Word
The two 32-bit Key 2 Word registers are used to set the 64-bit cryptographic key used for encryption/decryption.
TDES_KEY2WR0.KEY2W refers to the first word of the key and TDES_KEY2W1.KEY2W to the last one.
These registers are write-only to prevent the key from being read by another application.
TDES_KEY2WRx registers are not used in DES mode.
In XTEA mode, the key is defined on 128 bits. These registers contain the 64 MSB bits of the encryption/decryption key.
TDES_KEY2WRy registers are not used if the Private Key internal register is selected instead by writing a 1 to TDES_MR.PKRS.