DS785UM1
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Copyright 2007 Cirrus Logic
1/10/100 Mbps Ethernet LAN Controller
EP93xx User’s Guide
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Receive Descriptor Format - First Word
Definition:
Receive Descriptor, first word. Contains the base address to the data buffer.
Bit Descriptions:
BA:
Buffer Address. This location holds the 32 bit address
pointer to the data buffer, this must point to a word aligned
location.
Receive Descriptor Format - Second Word
Definition:
Receive Descriptor, second word. Contains control, index and length for the
descriptor.
Bit Descriptions:
NSOF:
Not Start of Frame. When the Not Start Of Frame bit is set
in a descriptor, the associated buffer will only be used for a
frame being continued from another buffer. If there is not a
frame to be continued (that is, start of a new frame), the
buffer will be discarded. When a buffer is discarded in this
manner, there is no status posted.
BI:
Buffer Index. The buffer index is provided for Host
software purposes. The MAC keeps an internal copy of the
index and includes it with any status writes associated with
a receive buffer.
BL:
Buffer Length. The Buffer Length contains the number of
bytes available to be used in the receive buffer. This
should be an integral number of words. If the length is set
to zero, the descriptor will be ignored and no status will be
posted for the buffer.
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Summary of Contents for EP93 Series
Page 28: ...P 6 DS785UM1 Copyright 2007 Cirrus Logic Preface EP93xx User s Guide PP P ...
Page 162: ...5 36 DS785UM1 Copyright 2007 Cirrus Logic System Controller EP93xx User s Guide 55 5 ...
Page 576: ...15 18 DS785UM1 Copyright 2007 Cirrus Logic UART2 EP93xx User s Guide 1515 15 ...
Page 634: ...17 38 DS785UM1 Copyright 2007 Cirrus Logic IrDA EP93xx User s Guide 1717 17 ...
Page 648: ...19 6 DS785UM1 Copyright 2007 Cirrus Logic Watchdog Timer EP93xx User s Guide 1919 19 ...
Page 688: ...21 32 DS785UM1 Copyright 2007 Cirrus Logic I2S Controller EP93xx User s Guide 2121 21 ...
Page 790: ...27 20 DS785UM1 Copyright 2007 Cirrus Logic IDE Interface EP93xx User s Guide 2727 27 ...
Page 808: ...28 18 DS785UM1 Copyright 2007 Cirrus Logic GPIO Interface EP93xx User s Guide 2828 28 ...