Datasheet

Table 14-7. DES DMA Mode (continued)
ValueRegister/Bit Field/Programming ModelStep
-DES_DATA_H[31:0] DATA_HLoad the input buffer data HSW register.
14.5.3 DES Events Servicing
14.5.3.1 Interrupt Servicing
This section describes the event servicing of the module. Figure 14-6 on page 1023 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
START
Read interrupt status register
int_status = DES_S_IRQSTATUS
Read the encrypt/decrypted data
result_L = DES_S_DATA_L[31:0] DATA_L
result_H = DES_S_DATA_H[31:0] DATA_H
END
yes
Is interrupt caused
from data input event?
DES_S_IRQSTATUS[1]
DATA_IN = 0x1
no
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-
yes
Is interrupt
caused from context input?
DES_S_IRQSTATUS[0]
CONTEX_IN == 0x1
no
Clear interrupt status
DES_S_IRQSTATUS[2:0] = 0x0
Service context input
event
14.5.3.2 Context Input Event Servicing
This section describes the context input event servicing of the module, as shown in Figure
14-7 on page 1024. The registers used during event servicing are: DES_CTRL, DES_SYSCONFIG,
DES_KEY1_L, DES_KEY1_H, DES_KEY2_L, DES_KEY2_H, DES_KEY3_L, DES_KEY3_H,
DES_IV_L, DES_IV_H, and DES_LENGTH.
1023June 18, 2014
Texas Instruments-Production Data
Tiva
™
TM4C129ENCPDT Microcontroller