ER
ECR
ESR
CER
EER
EECR
EESR
SER
SECR
IER
IECR
IESR
IPR
ICR
IEVAL
QER
QEER
QEECR
QEESR
QSER
QSECR
Physical register
01C0 1000h
01C0 1094h
DRAE0
ER
QSECR
IEVAL
Shadow region 0
registers
Access address
01C0 2000h
01C0 2094h
except IEVAL
registers
DRAE3
01C0 2694h
01C0 2600h
Access address
Shadow region 3
IEVAL
QSECR
ER
Shadow region 0
QRAE0
QRAE3
Architecture
605
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Enhanced Direct Memory Access (EDMA3) Controller
Figure 17-11. Shadow Region Registers
17.2.7.2 Channel Controller Shadow Regions
For each EDMA3 shadow region (and associated memory-maps) there is a set of registers associated
with the shadow region that allows association of the DMA/QDMA channels and interrupt completion
codes to the region. These registers are user-programmed per region to assign ownership of the
DMA/QDMA channels and TCC values to a region.
•
DRAE
m
: One register exists for each of the shadow regions. The number of bits in each register
matches the number of DMA channels. These registers need to be programmed to assign ownership
of DMA channels to the respective region. Accesses to DMA event registers and interrupt registers via
the shadow region address map are filtered through DRAE. A value of 1 in the corresponding DRAE bit
implies that the corresponding DMA/interrupt channel is accessible; a value of 0 in the corresponding
DRAE bit forces writes to be discarded and returns a value of 0 for reads.
•
QRAE
m
: One register exists for every region. The number of bits in each register matches the number
of QDMA channels. These registers must be programmed to assign ownership of QDMA channels to
the respective region. To enable a channel in a shadow region using shadow region 0 QEER, the
respective bit in QRAE must be set or writing into QEESR will not have the desired effect.
It is typical for an application to have a unique assignment of QDMA/DMA channels (and, therefore, a
given bit position) to a given region.
The use of shadow regions allows for restricted access to EDMA3 resources (DMA channels, QDMA
channels, TCC, interrupts) by tasks/cores/EDMA3 programmers in a system by setting or clearing bits in
the DRAE/QRAE registers. If exclusive access to any given channel/TCC code is required for a region,
then only that region's DRAE/QRAE should have the associated bit set.