RM0082
BS_DMA controller
Doc ID 018672 Rev 1
347/844
19.7.20
DMACCn control register
The DMACCnControl is a RW register which contains control information about the DMA
channel n, such as transfer size, burst size and transfer width. The DMACCnControl bit
assignments are given in
.
Software programs the DMACCnControl register directly before the appropriate DMA
channel is enabled. Once the corresponding DMA channel is enabled, this register is
updated by following the linked list when a complete packet of data has been transferred.
Reading the register when the DMA channel is active does not provide useful information.
This is because by the time the software has processed the value read, the channel might
have progressed. It is intended to be read-only when the channel has stopped.
Table 299.
DMACCnControl register bit assignments
Bit
Name
Reset value Description
[31]
I
1’h0
Terminal count interrupt enable.
This bit controls whether the current LLI is expected to trigger
the terminal count interrupt.
[30:28]
Port
3’h0
Protection.
This 3 bits field reports AHB access information which are
primarily intended to be used by source and destination
peripherals for implementing some level of protection. This field
directly controls the AHB
HPROT[3:1]
signals, and bit
assignment is given:
[28], HPROT[1] = 1‘b0 user mode
[28], HPROT[1] = 1‘b1 privileged mode
[29], HPROT[2] = 1‘b0 non-bufferable
[29], HPROT[2] = 1‘b1 bufferable
[30], HPROT[3] = 1‘b0 non-cacheable
[30], HPROT[3] = 1‘b1 cacheable
[27]
DI
1’h0
Destination increment.
If the bit is set, the destination (resp. source) address is
incremented after each transfer.
[26]
SI
1’h0
Source increment.
If the bit is set, the destination (resp. source) address is
incremented after each transfer.
[25]
D
1’h0
Destination AHB master select.
This bit allows to select the AHB master for the destination
(resp. source) transfer, according to encoding:
1‘b0 = AHB master 1.
1‘b1 = AHB master 2.
[24]
S
1’h0
Source AHB master select.
This bit allows to select the AHB master for the destination
(resp. source) transfer, according to encoding:
1‘b0 = AHB master 1.
1‘b1 = AHB master 2.