K60P100M100SF2RM Datasheet, PDF (1223/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

Chapter 44 10/100-Mbps Ethernet MAC (ENET)
44.4.15.2 Data Structure Examples
63
55
Word 0 Source address
1
Payload
2
3
47
39
31
23
15
7
Destination address
Length
(low)
Length
(high)
Source address (cont.)
Payload (cont.)
Payload (cont.)
Bits 0–7
transmitted
first
N
Unused (0x00)
Payload Payload Payload
(last)
(last-1) (last-2)
Figure 44-64. Normal Ethernet Frame 64-bit Mapping Example
63
55
47
39
31
23
15
7
Word 0 Source address
Destination address
1 VLAN info VLAN info VLAN tag VLAN tag
(low)
(high)
(0x00)
(0x81)
Source address (cont.)
2
Payload
Length
(low)
Length
(high)
3
Payload (cont.)
Bits 0–7
transmitted
first
N
Unused (0x00)
Payload Payload Payload
(last)
(last-1) (last-2)
Figure 44-65. VLAN tagged Frame 64-bit Mapping Example
If CRC forwarding is enabled (CRCFWD = 0), the last four valid octets of the frame
contain the FCS field. The non-significant bytes of the last word can have any value.
44.4.15.3 Frame Status
A MAC layer status word and an accelerator status word is available in the receive buffer
descriptor.
See Enhanced Buffer Descriptors for details.
The status is available with each frame with the last data of the frame.
If the frame status contains a MAC layer error (e.g., CRC or length error), RxBD[ME] is
also setwith the last data of the frame.
K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc.
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