BS_DMA controller
RM0082
346/844
Doc ID 018672 Rev 1
19.7.18 DMACCnDestAddr
register
The DMACCnDestAddr (channel n destination address) is a RW register which contains the
current destination address (byte-aligned) of the data to be transferred over the n-th DMA
channel. The DMACCnDestAddr bit assignments are given in
Note:
Source and destination addresses must be aligned to the source and destination widths.
Software programs the DMACCnDestAddr register directly before the appropriate DMA
channel is enabled. Once the corresponding DMA channel is enabled, this register is
updated:
●
as the destination address is incremented,
●
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, and in such
case, it shows the source address of the last item read.
19.7.19 DMACCnLLI
register
The DMACCnLLI (channel n linked list item) is a RW register which contains the address
(word-aligned) of the next Linked List Item (LLI). If next LLI is 0, then the current LLI is the
last in the chain, and the DMA channel is disabled after all DMA transfers associated with it
are completed. The DMACCnLLI bit assignments are given in
.
Note:
Programming this register when the corresponding DMA channel is enabled has
unpredictable results.
Table 296.
DMACCnSrcAddr register bit assignments
Bit
Name
Reset value
Description
[31:00]
SrcAddr
32’h0
DMA source address.
Table 297.
DMACCnDestAddr register bit assignments
Bit
Name
Reset value Description
[31:00]
DestAddr
32’h0
DMA destination address.
Table 298.
DMACCnLLI register bit assignments
Bit
Name
Reset value
Description
[31:02]
LLI
30’h0
Next LLI address.
This field contains the bits [31:2] of the address for the next
LLI. Address LSB bits [1:0] are 1‘b0 both.
[01]
Reserved
-
Read: undefined. Write as zero.
[00]
LM
1’h0
AHB master select.
This bit allows to select the AHB master for loading the next
LLI, according to encoding:
1‘b0 = AHB master 1.
1‘b1 = AHB master 2.