Altera Arria V Avalon-ST - Manual (Page 182)

Addr Register Name
Bits[31:24] Bits[23:16] Bits[15:0]
0x24 DMA Wr Status Lo Target Mem Address
Width
Write DMA Performance Counter. (Clock
cycles from time DMA header programmed
until last descriptor completes, including time
to fetch descriptors.)
0x28 DMA Rd Status Hi For field definitions refer to Fields in the DMA Read Status High
Register below.
0x2C DMA Rd Status Lo Max No. of Tags Read DMA Performance Counter. The
number of clocks from the time the DMA
header is programmed until the last descriptor
completes, including the time to fetch descrip‐
tors.
0x30 Error Status Reserved Error Counter. Number of
bad ECRCs detected by
the Application Layer.
Valid only when ECRC
forwarding is enabled.
The following table describes the fields of the DMA write status register. All of these fields are read only.
Table 16-5: Fields in the DMA Write Status High Register
Bit Field Description
[31:28] CDMA version Identifies the version of the chaining DMA example design.
[27:24] Reserved —
[23:21] Max payload size The following encodings are defined:
• 001 128 bytes
• 001 256 bytes
• 010 512 bytes
• 011 1024 bytes
• 100 2048 bytes
[20:17] Reserved —
16 Write DMA descriptor
FIFO empty
Indicates that there are no more descriptors pending in the write
DMA.
16-12 Chaining DMA Control and Status Registers
2014.12.15
Altera Corporation Testbench and Design Example
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