11-34
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)
Summary of Contents for DigitalDNA ColdFire MCF5272
Page 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
Page 38: ...xxxviii MCF5272 User s Manual TABLES Table Number Title Page Number ...
Page 58: ...1 10 MCF5272 User s Manual MCF5272 Specific Features ...
Page 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Page 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Page 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Page 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
Page 338: ...13 44 MCF5272 User s Manual Application Examples ...
Page 414: ...18 6 MCF5272 User s Manual PWM Programming Model ...
Page 452: ...19 38 MCF5272 User s Manual Power Supply Pins ...
Page 482: ...20 30 MCF5272 User s Manual Reset Operation ...
Page 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...