Texas Instruments Development Kit for TM4C129x,Tiva™ ARM® Cortex™ -M4 Microcontroller DK-TM4C129X DK-TM4C129X 데이터 시트
제품 코드
DK-TM4C129X
Figure 14-4. DES3DES-CFB Feedback Mode
Input buffer
(plain text)
DES core
(encrypt)
Output buffer
(cipher text)
Key register
128
64
192
data_in
data_out
Key in
Encryption
Temporary
register
64
64
64
IV register
64
Input buffer
(cipher text)
DES core
(encrypt)
Output buffer
(plain text)
Key register
64
64
192
data_in
data_out
Key in
Decryption
Temporary
register
64
64
64
IV register
64
14.5
DES Module Programming Guide -Low Level Programming Models
14.5.1
Surrounding Modules Global Initialization
14.5.1.1
Main Sequence - DES Global Initialization
This procedure initializes the DES after a POR.
Table 14-3. DES Global Initialization
Value
Register/Bit Field/Programming Model
Step
0x1
DES_SYSCONFIG[1] SOFTRESET
Execute software reset.
= 0x1
DES_SYSSTATUS[0] RESETDONE
Wait for reset to complete
0x0
DES_SYSCONFIG[3:2] SIDLE
Select force idle mode
See the programming models
Select the algorithm type (DES or 3DES)
-
DES_CTRL[5:4] MODE
Select the operating mode (ECB, CBC or CFB).
≠ 0x0
DES_CTRL[5:4] MODE
IF: ECB operating mode not selected.
-
DES_IV_L[31:0] IV_L
Load the initialization vector LSW.
-
DES_IV_H[31:0] IV_H
Load the initialization vector MSW.
-
DES_LENGTH[31:0] LENGTH
Define the cryptographic data length.
ENDIF
-
DES_CTRL[2] DIRECTION
Select encryption or decryption.
14.5.1.2
Subsequence - Configure the DES Algorithm Type
This subsequence details the DES algorithm type settings.
1043
December 13, 2013
Texas Instruments-Advance Information
Tiva
™
TM4C129XNCZAD Microcontroller