Figure 17-13: Receive Descriptor Fields Format
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TDES0
O
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Status [30:0]
TDES1
C
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RES
[30:29]
Buffer 2 Byte Count [28:16]
Ctrl
[15:14]
R
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Buffer 1 Byte Count [12:0]
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Receive Descriptor Field 0 (RDES0)
Table 17-14: Receive Descriptor Field 0 (RDES0)
Description
Bit
OWN: Own Bit
When set, this bit indicates that the descriptor is owned by the DMA of the EMAC. When
this bit is reset, this bit indicates that the descriptor is owned by the Host. The DMA clears
this bit either when it completes the frame reception or when the buffers that are associated
with this descriptor are full.
31
AFM: Destination Address Filter Fail
When set, this bit indicates a frame that failed in the DA Filter in the MAC.
†
30
Altera Corporation
Ethernet Media Access Controller
17-43
Receive Descriptor Field 0 (RDES0)
cv_54017
2013.12.30