Product specifications

VT8237R Data Sheet
Revision 2.06 December 15, 2004 -153- Device 18 Function 0 LAN Registers
Offset 08 – Command 0 (00h) ..........................................RW
7 Reserved ........................................ always reads 0
6 Receive Poll Demand ............................... default = 0
If this bit is set to 1, the Receive Descriptor (RD) will
be polled once (this bit will be cleared by hardware
after the polling is complete)
5 Transmit Poll Demand ............................ default = 0
If this bit is set to 1, the Transmit Descriptor (TD)
will be polled once (this bit will be cleared by
hardware after the polling is complete)
4 Transmit Process
0 Transmit engine disabled .......................default
1 Transmit engine enabled (transmit may occur)
3 Receive Process
0 Receive disabled ....................................default
1 Receive enabled
2 Stop NIC
0 NIC enabled ...........................................default
1 NIC disabled (transmit/receive cannot occur)
1 Start NIC
0 No command entered .............................default
1 Start the NIC
0 Reserved ..................................... Do not program
Offset 09 – Command 1 (00h).......................................... RW
7 Software Reset
0 No reset ................................................. default
1 Reset the MAC
6 Receive Poll Demand 1.............................default = 0
This bit functions the same as Rx8[6]. The function
can be enabled by setting either bit (for backward
compatibility).
5 Transmit Poll Demand 1.......................... default = 0
This bit functions the same as Rx8[5]. The function
can be enabled by setting either bit (for backward
compatibility).
4 Reserved ........................................always reads 0
3 TD / RD Auto Polling
0 Enable (polling interval is determined by
Rx6F[2:0] )............................................ default
1 Disable
2 Full Duplex
0 Set MAC to half duplex mode............... default
1 Set MAC to full duplex mode
1-0 Reserved ......................................Do not program