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MCF5272 User’s Manual
Buffer Descriptors
11.6.1.1 Ethernet Receive Buffer Descriptor (RxBD)
In the RxBD, the user initializes the E and W bits in the first word and the pointer in the
second word. When the buffer has been sent as a DMA, the FEC will modify the E, L, M,
LG, NO, SH, CR, and OV bits and write the length of the used portion of the buffer in the
first word. The M, LG, NO, SH, CR, and OV bits in the first word of the buffer descriptor
are modified by the FEC only when the L bit is set.
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
+0
E
RO1
W
RO2
L
—
M
BC
MC
LG
NO
SH
CR
OV
TR
+2
DATA LENGTH
+4
Rx Data Buffer Pointer A[31–16]
+6
Rx Data Buffer Pointer A[15–0]
Figure 11-26. Receive Buffer Descriptor (RxBD)
Содержание DigitalDNA ColdFire MCF5272
Страница 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
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Страница 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Страница 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Страница 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Страница 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
Страница 338: ...13 44 MCF5272 User s Manual Application Examples ...
Страница 414: ...18 6 MCF5272 User s Manual PWM Programming Model ...
Страница 452: ...19 38 MCF5272 User s Manual Power Supply Pins ...
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Страница 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...
Страница 548: ...INDEX Index 12 MCF5272 User s Manual ...