Intel PCI User Manual

379

The following examples are provided as suggestions for configuring common settings between the 

MAC and an Ethernet controller attached in the GMII/MII mode. 
•  MAC duplex and speed settings forced by software based on resolution of PHY 

(CTRL.FRCDPLX = 1b, CTRL.FRCSPD = 1b, CTRL.ASDE = don’t care)

CTRL.FD

Set by software based on reading PHY status register after 

PHY has autonegotiated a successful link-up.

CTRL.SLU Must be set to 1b by software to enable communications 

between MAC and PHY

CTRL.RFCE Must be set by S/W after reading flow control resolution from 

PHY registers

CTRL.TFCE - Must be set by S/W after reading flow control resolution from PHY registers

CTRL.SPEED

Set by software based on reading PHY status register after 

PHY has autonegotiated a successful link-up.

STATUS.FD  Reflects the MAC forced duplex setting written to CTRL.FD
STATUS.LU  Reflects link indication (LINK) from PHY qualified with 

CTRL.SLU (set to 1b)

STATUS.SPEED  Reflects MAC forced speed setting written in 

CTRL.SPEED

•  MAC duplex setting forced by software based on resolution of PHY; speed auto-detected by 

MAC
(CTRL.FRCDPLX = 1b, CTRL.FRCSPD = 0b, CTRL.ASDE = 1b)

CTRL.FD

Set by software based on reading PHY status register after 

PHY has autonegotiated a successful link-up.

CTRL.SLU Must be set to 1b by software to enable communications 

between MAC and PHY

CTRL.RFCE Must be set by S/W after reading flow control resolution from 

PHY registers

CTRL.TFCE ..............

Must be set by S/W after reading flow control resolution from PHY 

registers

CTRL.SPEED

Don’t care; speed setting is calculated by the MAC based 

on signals from the PHY after PHY has autonegotiated a successful 
link-up 

STATUS.FD Reflects the MAC forced duplex setting written to CTRL.FD
STATUS.LU  Reflects link indication (LINK) from PHY qualified with 

CTRL.SLU (set to 1b)

STATUS.SPEED  Reflects actual speed setting calculated by MAC ASD 

function