LAN83C175 Datasheet, PDF (57/92 Pages) SMSC Corporation – Ethernet CARDBUS Integrated Controller With Modem Support

4 - UNDERRUN: This bit is set when the
transmit DMA is unable to supply the
transmitter enough data to maintain frame
transmission.
3 - CARRIER SENSE LOST: This bit is set if
the carrier is lost during packet transmission.
Carrier sense is monitored from its rising edge
at the start of the outgoing frame’s echo.
Transmission is not aborted upon loss of
carrier. This bit will always return zero in full
duplex mode.
2 - TRANSMITTED WITH COLLISIONS:
When set, this bit indicates the frame collided
at least once with another frame on the
network. It is not set for either out-of-window
collisions or excessive collision aborts.
1 - NON-DEFERRED TRANSMISSION: This
bit is set if the frame was transmitted
successfully without deferring. A deferred
transmission can only occur the first time an
attempt is made to send a packet. Collisions
are not deferred transmissions.
0 - PACKET TRANSMITTED: This bit is set to
indicate transmission of a packet without
excessive collisions or abort.
E8 - TRANSMIT RAM BUFFER
Reset Value: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
31 through 0 - The transmit ram can be read and
written through this I/O port (for test purposes
only). The read or write will occur at the address
specified in the PTLCAR register. The PTLCAR
register will be incremented by four (one dword)
each time this port is read or written.
EC - CardBus TRANSMIT 2 FIRST
DESCRIPTOR ADDRESS
Reset Value: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx00
If two frames are loaded into the local transmit
ram, this register contains the byte address of the
first descriptor for the second transmit packet. It
is the location in host memory where the transmit
status will be posted when transmission of that
frame is complete. The two lsb’s are fixed at zero
so the address will always be dword aligned.
31 through 2 - CardBus Address.
1 and 0 - Not writable - always return zeroes.
57