lan91c95 Standard Microsystems Corp., lan91c95 Datasheet - Page 105

• Manufacturer Part Number: lan91c95
• Description: Isa/pcmcia Full Duplex Single-chip Ethernet And Modem Controller With Ram
• Manufacturer: Standard Microsystems Corp.

Reverse Polarity Function
In the 10BASE-T mode, the PHY monitors for
receiver polarity reversal due to crossed wires
and corrects by reversing the signal internally.
Collision Detection Function
In the 10BASE-T mode, while in half duplex, a
collision state is indicated when there are
simultaneous transmissions and receptions on
the twisted pair link. During a collision state, the
nCOLL signal is asserted. If the received data
ends and the transmit control signal is still
active, the transmit data is sent to the MAC
within 9 bit times. The nnCOLL signal is de-
asserted within 9 bit times after the collision
terminates.
In the AUI mode, the external
105
transceiver sends a 10MHz signal to the PHY
upon detection of a collision.
Link Integrity
The PHY test for a faulty twisted-pair link. In the
absence of transmit data, link test pulses are
tranmsitted every 16+/-18ms after the end of the
last transmission or link pulse on the twisted
pair medium. If neither valid data nor link test
pulses are received within 10 to 150ms, the link
is declared bad and both data transmission as
well as the operational loopback function are
disabled.
disabled
networks.
The Link Integrity function can be
for
pre-10BASE-T
twisted-pair