DMALPEND
DMAEND
Figure 16-31: Aligned Burst with Unaligned MFIFO Buffer Width
0
3
a
b
a
Data from
DMALD
DMAST
Data for
DMAST
7
In this example, the destination address is not 64-bit aligned, it requires three rather than the expected two
MFIFO buffer entries.
This example has a static requirement of zero MFIFO buffer entries and a dynamic requirement of three
MFIFO buffer entries.
Fixed Transfers
Fixed Destination with Aligned Address
In this program, the source address and destination address are aligned with the AXI data bus width, and
the destination address is fixed.
DMAMOV CCR, SB2 SS64 DB4 DS32 DAF
DMAMOV SAR, 0x1000
DMAMOV DAR, 0x4000
DMALP 16
DMALD ; shown as a in the figure below
DMAST ; shown as b in the figure below
DMALPEND
DMAEND
Figure 16-32: Fixed Destination with Aligned Address
Each DMALD in the program loads two 64-bit data transfers into the MFIFO buffer. Because the destination
address is a 32-bit fixed address, then the DMAC splits each 64-bit data item across two entries in the MFIFO
buffer.
0
4
a
b
Data from
DMALD
a
0
7
Data for
DMAST
DMALD
DMAST
a
This example has a static requirement of zero MFIFO buffer entries and a dynamic requirement of four
MFIFO buffer entries.
Altera Corporation
DMA Controller
16-51
Fixed Transfers
cv_54016
2013.12.30