Product specifications

VT8235 V-Link South Bridge
Revision 1.22 October 24, 2002 -124- Device 18 Function 0 LAN Registers
Offset 43-40 – Transmit Status (0000 0000h)..................RW
31 Descriptor Owner
0 Descriptor Owned By Host (NIC cannot
access descriptor)
1 Descriptor Owned by NIC (NIC can access
descriptor)
This bit has no default so must be set by the driver at
initialization.
30-16 Reserved ........................................ always reads 0
15 Transmit Error................................. RO, default = 0
0 Transmit Successful .............................. default
1 Excessive Collisions During Transmit Attempt
14 Reserved ........................................ always reads 0
13 System Error .................................... RO, default = 0
12 Invalid TD Format or Structure or TD Overflow
...................................... RO, default = 0
11 Transmit Data FIFO Underflow........... RO, def = 0
10 Carrier Sense Lost During Transmit ... RO, def = 0
9 Out of Window Collision....................... RO, def = 0
(collision outside initial 64 bytes)
8 Transmit Abort (Excessive Collisions) . RO, def = 0
7 CD Heartbeat Issued (10BaseT Only)... RO, def = 0
6-5 Reserved ........................................ always reads 0
4 Collision Detected During Transmit..... RO, def = 0
3-0 Collision Retry Count............................ RO, def = 0
Offset 47-44 – Tx Data Buffer Control (0000 0000h)......RO
31-24 Reserved ........................................always reads 0
23 Send-Complete Interrupt
0 Interrupt not generated...........................default
1 Interrupt generated after send complete
22 End of Transmit Packet
For packets too large to fit into a single transmit
descriptor and thus occupy multiple TD’s, this bit
reports whether this TD is the End TD.
0 This TD is not the End TD ....................default
1 This TD is the End TD
21 Start of Transmit Packet
For packets too large to fit into a single transmit
descriptor and thus occupy multiple TD’s, this bit
reports whether this TD is the Start TD.
0 This TD is not the Start TD ...................default
1 This TD is the Start TD
20-17 Reserved ........................................always reads 0
16 Disable CRC Generation .........................default = 0
15 Chain Buffer .............................................default = 0
14-11 Reserved ........................................always reads 0
10-0 Tx Data Buffer Size..................................default = 0
The transmit data buffer size for this descriptor. The
total byte count of the entire frame will be stored in
the last descriptor.
Offset 4B-48 – Tx Data Buffer Start Address..................RO
31-0 Tx Data Buffer Start Address
Offset 4F-4C – Tx Data Buffer Branch Address.............RO
31-4 Tx Data Buffer Branch Address
3-1 Reserved ........................................always reads 0
0 Tx Interrupt Enable
0 Issue interrupt for this packet.................default
1 No interrupt generated