91C94 Datasheet, PDF (40/120 Pages) SMSC Corporation – ISA/PCMCIA SINGLE CHIP ETHERNET CONTROLLER WITH RAM

I/O SPACE - BANK0
OFFSET
NAME
4
RECEIVE CONTROL REGISTER
TYPE
READ/WRITE
SYMBOL
RCR
HIGH BYTE
SOFT RST FILT_CAR
0
0
0
0
STRIP CRC ^RXEN
0
0
0
0
0
0
0
0
LOW BYTE
ALMUL
PRMS
RX_
ABORT
0
0
0
0
0
0
0
0
SOFT_RST - Software activated Reset. Active
high. Valid for ISA and PCMCIA. Initiated by
writing this bit high and terminated by writing the
bit low. LAN91C94 configuration is not
preserved, except for Configuration, Base, IA0-
5, COR, and CSR Registers. EEPROM is not
reloaded after software reset.
FILT_CAR - Filter Carrier. When set filters
leading edge of carrier sense for 12 bit times.
Otherwise recognizes a receive frame as soon
as carrier sense is active.
STRIP_CRC - When set it strips the CRC on
received frames. When clear the CRC is stored
in memory following the packet. Defaults low.
RXEN - Enables the receiver when set. If
cleared, completes receiving current frame and
then goes idle. Defaults low on reset.
ALMUL - When set accepts all multicast frames
(frames in which the first bit of DA is '1'). When
clear accepts only the multicast frames that
match the multicast table setting. Defaults low.
PRMS - Promiscuous mode. When set receives
all frames, regardless of their destination
address. Does not receive its own transmission
unless FDUPX = 1.
RX_ABORT - This bit is set if a receive frame
was aborted due to length longer than 1532
bytes. The frame will not be received. The bit is
cleared by RESET or by the CPU writing it low.
Packet Too Long
Run out of Memory
During Receive
RX_ABORT
1
1
RX_OVRN_ INT
0
1
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