SMC Networks SMC91C95 User Manual

Page 68

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68

I/O SPACE - BANK 3

OFFSET

NAME

TYPE

SYMBOL

C

EARLY RCV REGISTER

READ/WRITE

ERCV

HIGH

BYTE

0

0

1

1

0

0

1

1

LOW

BYTE

RCV

DISCR

D

ERCV THRESHOLD

0

0

0

1

1

1

1

1

RCV DISCRD - Set to discard a packet being
received. This bit can be used in conjunction with
ERCV THRESHOLD and ERCV INT to process a
packet header while it is being received and sicard
it if the packet is not desired. Setting this bit will
only discard packets that are still in the process of
being received.

If the RCV DISCRD bit is set prior to the end of a
receive packet, RXOVRN bit in the Interrupt Status
Register will be set to indicate that the packet was
discarded and its memory released. If the receive

packet is complete prior to the RCV DISCRD bit
being set, the packet is received normally and
RCV INT bit is set in the Interrupt Status Register.
The RCV DISCRD bit is self-clearing.

ERCV THRESHOLD - Threshold for ERCV
interrupt. Specified in 64 byte multiples. Whenever
the number of bytes written in memory for the
presently received packet exceeds the ERCV
THRESHOLD, ERCV INT bit of the
INTERRUPT STATUS REGISTER is set.

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