TC5299J Datasheet, PDF (20/32 Pages) List of Unclassifed Manufacturers – FAST ETHERNET PCMCIA LAN CONTROLLER

TC5299J
D1,D2 LB0,LB1
D3
-
D4
OFST
D5
-
D6
-
D7
-
0: CRC appended by transmitter
1: CRC inhibited by transmitter
Encoded Loopback Control: These encoded configuration bits set the type of
loopback that is to be performed. Note that loopback in mode 2 sets the LPBK pin
high, this places the TC5299J in loopback mode and that D2 of the DCR must be
set to zero for loopback operation.
LB1
LB0
Mode0
0
0
Normal Operation (LPBK=0)
Mode1
0
1
Internal Loopback (LPBK=0)
Reserved
1
0
Reserved
1
1
Reserved
Collision Offset Enable: This bit modifies the back off algorithm to allow
prioritization of nodes.
0: Backoff Logic implements normal algorithm.
1: Forces Backoff algorithm modification to 0 to 2^mim(3+n,10) slot times for first three
collisions, Then follows standard backoff. (For first three collisions station has
higher average backoff delay making a low priority mode.)
Reserved
Reserved
Reserved
5.7.4 Transmit Status Register (TSR)
04H(Read)
This register records events that occur on the media during transmission of a packet. It is cleared, when
the next transmission is initiated by the host. All bits remain low unless the event that corresponds to a
particular bit occurs during transmission. Each transmission should be followed by a read of this register.
The contents of this register are not specified until after the first transmission.
7
6
OWC
5
4
3
2
1
0
FU
CRS ABT COL
-
PTX
Bit
Symbol
D0
PTX
D1
-
D2
COL
D3
ABT
D4
CRS
D5
FU
D6
-
D7
OWC
Description
Packet Transmitted: Indicates transmission without error (No excessive collisions
or FIFO underrun) (ABT=”0”, FU=”0”).
Reserved
Transmit Collided: Indicates that the transmission collided at least once with
another station on the network. The number of collisions is recorded in the
Number of Collisions Registers. (NCR).
Transmit Aborted: Indicates the TC5299J aborted transmission because of
excessive collisions. (Total number of transmissions including original
transmission attempt equals 16).
Carrier Sense Lost: This bit is set when carrier is lost during transmission of the
packet. Carrier Sense is monitored from the end of Preamble/Synch until TXE is
dropped. Transmission is not aborted on loss of carrier.
FIFO Underrun: If the TC5299J cannot gain access of the bus before the FIFO
empties, this bit is set. Transmission of the packet will be aborted.
Reserved
Out of Window Collision: Indicates that a collision occurred after a slot time.
Transmissions rescheduled as in normal collisions.
-20-
Ver. 0.1
07/04/01