DES Registers
867
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Data Encryption Standard Accelerator (DES)
14.7.4 DES_CTRL Register (Offset = 0x20) [reset = 0x80000000]
DES Control (DES_CTRL)
DES_CTRL is shown in
and described in
Return to
Figure 14-11. DES_CTRL Register
31
30
29
28
27
26
25
24
CONTEXT
RESERVED
R-0x1
R-0x0
23
22
21
20
19
18
17
16
RESERVED
R-0x0
15
14
13
12
11
10
9
8
RESERVED
R-0x0
7
6
5
4
3
2
1
0
RESERVED
MODE
TDES
DIRECTION
INPUT_READY
OUTPUT_REA
DY
R-0x0
R/W-0x0
R/W-0x0
R/W-0x0
R-0x0
R-0x0
Table 14-13. DES_CTRL Register Field Descriptions
Bit
Field
Type
Reset
Description
31
CONTEXT
R
0x1
If 1, this read-only status bit indicates that the context data registers
can be overwritten and the host is permitted to write the next
context.
30-6
RESERVED
R
0x0
5-4
MODE
R/W
0x0
Select CBC, ECB or CFB mode
0x0 = ECB mode
0x1 = CBC mode
0x2 = CFB mode
0x3 = reserved
3
TDES
R/W
0x0
Select DES or triple DES encryption/decryption.
0x0 = DES mode
0x1 = TDESmode
2
DIRECTION
R/W
0x0
Select encryption/decryption
0x0 = decryption is selected
0x1 = Encryption is selected
1
INPUT_READY
R
0x0
When 1, ready to encrypt or decrypt data
0
OUTPUT_READY
R
0x0
When 1, Data decrypted/encrypted ready