START
END
yes
Is interrupt caused
From data input event?
DES_S_IRQSTATUS[1]
DA_TA_IN=0x1
no
A_H = 0x-
yes
no
Service context input
event
Is interrupt caused
From context input?
DES_S_IRQSTATUS[0]
CONTEX_IN=0x1
Write the data to be
Encrypt/Decrypted
DES_S_DATA_L[31:0] DATA_L=0x-
DES_S_DATA_H[31:0] DATA_H=0x-
Read the
Encrypt/Decrypted data
DES_S_DATA_L[31:0] DATA_L
DES_S_DATA_H[31:0] DATA_H
Read interrupt status register
Int_status = DES_S_IRQSTATUS
Clear interrupt status
DES_S_IRQSTATUS[2:0] = 0x0
DES Module Programming Guide – Low Level Programming Models
861
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Data Encryption Standard Accelerator (DES)
14.6.2.3 DES Interrupt DMA Mode
The following lists the DES DMA mode steps (see
1. Enable DES module DMA requests.
2. Load the input buffer data LSW register.
3. Load the input buffer data HSW register.
Table 14-7. DES DMA Mode
Step
Register / Bit Field / Programming Model
Value
1
DES_SYSCONFIG[7:5]
0x7
2
DES_DATA_L[31:0] DATA_L
-
3
DES_DATA_H[31:0] DATA_H
-
14.6.3 DES Events Servicing
14.6.3.1 Interrupt Servicing
This section describes the event servicing of the module.
shows the DES interrupt service.
The registers used during event servicing are: DES_IRQSTATUS, DES_DATA_L, and DES_DATA_H.
Figure 14-6. DES Interrupt Service