Texas Instruments TMS320C645x DSP - Manual (Page 27)

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SOP | EOP 60
0 60
pBuffer
pNext
Packet A
60 bytes
0
SOP
Fragment 1
Packet B
512
1514
pBuffer
pNext
512 bytes
EOP
0
0
−−−
Packet B
Fragment 3
500 bytes
502
pBuffer
−−−
500
pNext
−−−
pBuffer
pNext
Packet B
Fragment 2
502 bytes
SOP | EOP
0
1514 bytes
Packet C
1514
pBuffer
pNext (NULL)
1514
EMAC Functional Architecture
For example, consider three packets to be transmitted, Packet A is a single fragment (60 bytes), Packet B
is fragmented over three buffers (1514 bytes total), and Packet C is a single fragment (1514 bytes).
Figure 8 shows the linked list of descriptors to describe these three packets.
Figure 8. Typical Descriptor Linked List
SPRU975B – August 2006 Ethernet Media Access Controller (EMAC)/Management Data Input/Output (MDIO) 27
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