91C94 Datasheet, PDF (39/120 Pages) SMSC Corporation – ISA/PCMCIA SINGLE CHIP ETHERNET CONTROLLER WITH RAM

frame) or FORCOL in TCR was set to 1 by the
CPU. When detected the transmitter jams and
turns itself off clearing the TXENA bit in TCR.
Cleared by setting TXENA in TCR.
TX_DEFR - Transmit Deferred. When set,
carrier was detected during the first 6.4 usec of
the inter frame gap. Cleared at the end of every
packet sent.
LTX_BRD - Last transmit frame was a
broadcast. Set if frame was broadcast. Cleared
at the start of every transmit frame.
SQET - Signal Quality Error Test. The
transmitter opens a 1.6 us window 0.8 us after
transmission is completed and the receiver
returns inactive. During this window, the
transmitter expects to see the SQET signal from
the transceiver. The absence of this signal is a
'Signal Quality Error' and is reported in this
status bit. Transmission stops and EPH INT is
set if STP_SQET is in the TCR is also set when
SQET is set. This bit is cleared by setting
TXENA high.
16COL - 16 collisions reached. Set when 16
collisions are detected for a transmit frame.
TXENA bit in TCR is reset. Cleared when
TXENA is set high.
LTX_MULT - Last transmit frame was a
multicast. Set if frame was a multicast.
Cleared at the start of every transmit frame.
MULCOL - Multiple collision detected for the last
transmit frame. Set when more than one
collision was experienced. Cleared when
TX_SUC is high at the end of the packet being
sent.
SNGLCOL - Single collision detected for the last
transmit frame. Set when a collision is detected.
Cleared when TX_SUC is high at the end of the
packet being sent.
TX_SUC - Last transmit was successful. Set if
transmit completes without a fatal error. This bit
is cleared by the start of a new frame
transmission or when TXENA is set high.
Fatal errors are:
16 collisions
SQET fail and STP_SQET = 1
FIFO Underrun
Carrier lost and MON_CSN = 1
Late collision
39