Chaining dma descriptor tables, Chaining dma descriptor tables -12 – Altera Arria 10 Avalon-ST User Manual
Page 212

Bit
Field
Description
16
Write DMA descriptor
FIFO empty
Indicates that there are no more descriptors pending in the write
DMA.
[15:0]
Write DMA EPLAS
Indicates the number of the last descriptor completed by the write
DMA. For simultaneous DMA read and write transfers, EPLAST
is only supported for the final descriptor in the descriptor table.
The following table describes the fields in the DMA read status high register. All of these fields are read
only.
Table 17-6: Fields in the DMA Read Status High Register
Bit
Field
Description
[31:24]
Reserved
—
[23:21]
Max Read Request Size
The following encodings are defined:
• 001 128 bytes
• 001 256 bytes
• 010 512 bytes
• 011 1024 bytes
• 100 2048 bytes
[20:17]
Negotiated Link Width
The following encodings are defined:
• 4'b0001 ×1
• 4'b0010 ×2
• 4'b0100 ×4
• 4'b1000 ×8
16
Read DMA Descriptor
FIFO Empty
Indicates that there are no more descriptors pending in the read
DMA.
[15:0]
Read DMA EPLAST
Indicates the number of the last descriptor completed by the read
DMA. For simultaneous DMA read and write transfers, EPLAST
is only supported for the final descriptor in the descriptor table.
Chaining DMA Descriptor Tables
The following table describes the Chaining DMA descriptor table. This table is stored in the BFM shared
memory. It consists of a four-dword descriptor header and a contiguous list of
17-12
Chaining DMA Descriptor Tables
UG-01145_avst
2015.05.04
Altera Corporation
Testbench and Design Example