55.5.7 TDES Key 1 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_KEY1WRy |
| Offset: | 0x20 + y*0x04 [y=0..1] |
| Reset: | – |
| Property: | Write-only |
| Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
| KEY1W[31:24] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | – | – | – | – | – | – | – | – | |
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| KEY1W[23:16] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | – | – | – | – | – | – | – | – | |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| KEY1W[15:8] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | – | – | – | – | – | – | – | – | |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| KEY1W[7:0] | |||||||||
| Access | W | W | W | W | W | W | W | W | |
| Reset | – | – | – | – | – | – | – | – | |
Bits 31:0 – KEY1W[31:0] Key 1 Word
The two 32-bit Key 1 Word registers are used to set the 64-bit cryptographic key used for encryption/decryption.
TDES_KEY1WR0.KEY1W refers to the first word of the key and TDES_KEY1WR1.KEY1W to the last one.
These registers are write-only to prevent the key from being read by another application.
In XTEA mode, the key is defined on 128 bits. These registers contain the 64 LSB bits of the encryption/decryption key.
TDES_KEY1WRy registers are not used if the Private Key internal register is selected instead by writing a 1 to TDES_MR.PKRS.