Product specifications

VT8237R Data Sheet
Revision 2.06 December 15, 2004 -157- Device 18 Function 0 LAN Registers
Offset 6C – PHY Address (01h) .......................................RW
7-6 MII Management Polling Timer Interval (Polling
PHY)
00 1024 MDC Clock Cycles .......................default
01 512 MDC Clock Cycles
10 128 MDC Clock Cycles
11 64 MDC Clock Cycles
MDC is an internal clock with a 960 ns cycle time.
5 Accelerate MDC Speed
0 Normal ...................................................default
1 4x Accelerated
4-0 Extended PHY Device Address.......... default = 01h
Stored from EEPROM during power-up or EEPROM
auto-reload but can be programmed by software
Offset 6D – MII Status (13h)............................................RW
7 PHY Reset
0 PHY reset not asserted ...........................default
1 PHY reset asserted
6-5 Reserved ........................................ always reads 0
4 PHY Option
0 PHY address updated from EEPROM
1 Use default PHY address of 0001h .......default
3 PHY Device Received Error
0 No MII error...........................................default
1 MII Error
2 Reserved ........................................ always reads 0
1 Link Failure
0 Link successful
1 Link unsuccessful (no connection)........default
0 PHY Speed
0 100 Mb
1 10 Mb ....................................................default
Offset 6E – Buffer Control 0 (00h).................................. RW
7-3 Reserved ......................................Do not program
2-0 DMA Length
000 32 bytes 8 DW................................ default
001 64 bytes 16 DW
010 128 bytes 32 DW
011 256 bytes 64 DW
100 512 bytes 128 DW
101 1024 bytes 256 DW
11x Store & Forward
Offset 6F – Buffer Control 1 (00h) .................................. RW
7-3 Reserved ......................................Do not program
2-0 Polling Interval Timer
This field determines the polling interval when TX /
RX Auto-Polling is enabled (LAN I/O Rx09[3]=0).
000 2
13
V-Link Clocks.................................. default
001 2
15
V-Link Clocks
001 2
14
V-Link Clocks
001 2
12
V-Link Clocks
001 2
11
V-Link Clocks
001 2
10
V-Link Clocks
001 2
9
V-Link Clocks
001 2
8
V-Link Clocks