Ethernet Interface

Table 8-7. GMII/MII Mode – Auto-Speed Detection

CTRL.FRCSPD = CTRL.FRCDPLX = 0b; CTRL.ASDE = 1b

Control Bit

Effect on Control Bits

 

 

CTRL.FD

Duplex is set per internal duplex indication after link up assertion by PHY.

 

 

CTRL.SLU

Software should set to allow PHY to control.

 

 

CTRL.RFCE

Must be set by software after reading flow control resolution from MII

registers.

 

 

 

CTRL.TFCE

Must be set by software after reading flow control resolution from MII

registers.

 

 

 

CTRL.SPEED

Ignored; no impact on speed.

 

 

STATUS.FD

Reflects the value of CTRL.FD as above.

 

 

STATUS.LU

Reflects internal link status

 

 

STATUS.SPEED

Speed status bits reflect speed resolved from ASD function.

 

 

Table 8-8. GMII/MII Mode – Force Speed

CTRL.FRCSPD = 1b; CTRL.FRCDPLX = 0b; CTRL.ASDE = X

Control Bit

Effect on Control Bits

 

 

CTRL.FD

Duplex is set per internal duplex indicates input after link up assertion by PHY.

 

 

CTRL.SLU

Software should set to allow PHY to control.

 

 

CTRL.RFCE

Must be set by software after reading flow control resolution from MII

registers.

 

 

 

CTRL.TFCE

Must be set by software after reading flow control resolution from MII

registers.

 

 

 

CTRL.SPEED

Set by software to set speed of the MAC; must match PHY speed settings.

 

 

STATUS.FD

Reflects the value of CTRL.FD.

 

 

STATUS.LU

Reflects internal link status.

 

 

STATUS.SPEED

Speed status bits reflect speed forced by CTRL.SPEED.

 

 

168

Software Developer’s Manual

Page 182
Image 182
Intel Intel Gigabit Ethernet Controllers, PCI-X manual GMII/MII Mode Auto-Speed Detection, GMII/MII Mode Force Speed