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Serial Communication Controllers (SCCs)
MC68360 USER’S MANUAL
miscuous mode, the user can use the Miss bit to quickly determine whether the frame was
destined to this station. This bit is valid only if the L bit is set.
0 = The frame was received because of an address recognition hit.
1 = The frame was received because of promiscuous mode.
LG—Rx Frame Length Violation
A frame length greater than the maximum defined for this channel was recognized (only
the maximum-allowed number of bytes is written to the data buffer).
NO—Rx Nonoctet Aligned Frame
A frame that contained a number of bits not divisible by 8 was received, and the CRC
check that occurred at the preceding byte boundary generated an error.
SH—Short Frame
A frame length that was less than the minimum defined for this channel was recognized.
This indication is possible only if the RSH bit is set in the PSMR.
CR—Rx CRC Error
This frame contains a CRC error.
OV—Overrun
A receiver overrun occurred during frame reception.
CL—Collision
This frame was closed because a collision occurred during frame reception. This bit will
be set only if a late collision occurred or if the RSH bit is enabled in the PSMR. The late
collision definition is determined by the LCW bit in the PSMR.
Data Length
The data length is the number of octets written by the CP into this BD’s data buffer. It is
written by the CP once as the buffer is closed.
When this BD is the last BD in the frame (L = 1), the data length contains the total number
of frame octets (including four bytes for CRC).
NOTE
The actual amount of memory allocated for this buffer should be
greater than or equal to the contents of the MRBLR.
Rx Data Buffer Pointer
The receive buffer pointer, which always points to the first location of the associated data
buffer, may reside in either internal or external memory. This pointer must be divisible by
4.
7.10.23.19 ETHERNET TRANSMIT BUFFER DESCRIPTOR (TX BD). Data is presented
to the Ethernet controller for transmission on an SCC channel by arranging it in buffers ref-
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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