Sundance Spas ST201 - Manual (Page 86)

86
Sundance Technology ST201 PRELIMINARY draft 2
PHYCTRL
Class....................I/O Registers, External Interface Control
Base Address ......IoBaseAddress register value
Address Offset .....0x5e
Access Mode .......Read/Write
Width ...................8 bits
This register contains control bits for the MII Management Interface. The MII Management Interface is
used to access registers in an MII PHY device. The Management Interface is a two-wire serial interface
connecting ST201 to any MII-compliant PHY devices residing on the adapter. The host system operates
the Management Interface by writing and reading bit patterns to the PhyCtrl register which correspond to
the physical waveforms required on the interface signals. For more information on the Management Inter-
face signal protocols, refer to the Media Independent Interface standard of IEEE 802.3u Specification.
BIT BIT NAME BIT DESCRIPTION
0 MgmtClk The MII Management Clock. This bit drives directly the management
clock to the PHY device(s).
1 MgmtData The MII Management Data bit. When the MgmtDir bit (below) is set,
the value written to this bit is driven onto the MDIO signal. When Mgmt-
Dir is cleared, data being driven by the PMD can be read from this bit.
2 MgmtDir The MII data direction control bit. Setting this bit causes ST201 to drive
MDIO with the data bit written into MgmtData.
3 DisableClk25 This bit is set to tri-state the CLK25 pin. DisableClk25 is cleared upon
reset.
4 PhyDuplexPolarity Clearing this read/write bit will cause the PHYDPLXN input pin to be
active low. The default value for this bit upon reset is cleared.
5 PhyDuplexStatus This read-only bit provides a real-time indication of the duplex status of
the PHY. This bit is set for full duplex operation.
6 PhySpeedStatus This read-only bit provides a real-time indication of the speed status of
the PHY. This bit is set for 100Mb/s operation.
7 PhyLinkStatus This read-only bit provides a real-time indication of the twisted-pair
transceiver link. This bit is set for operational link (link status up).