SMC Networks SMC91C95

I/O SPACE - BANK0

OFFSET NAME TYPE SYMBOL

4RECEIVE CONTROL

HIGH

BYTE SOFT_

RST FILT_

CAR 0000STRIP_

CRC RXEN

00000000

LOW

BYTE ALMUL PRMS RX_

ABORT

00000000

SOFT_RST - Software activated Reset. Active

high. Initiated by writing this bit high and

terminated by writing the bit low. The SMC91C95

configuration is not preserved, except for

Configuration, Base, and IA0-IA5 Registers. The

EEPROM in both ISA and PCMCIA mode 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. Does not receive its own transmission

unless it is in full duplex.

RX_ABORT - This bit is set if a receive frame is

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.

RX_ABORT RX_OVRN_INT

Packet Too Long 1 0

Run out of Memory

During Receive 1 1