Posted on May 17, 2011 at 09:58In the code snipit below, from 91x_enet.c the ENET_MAC is fixed up based on the reprted result of auto-negotiation.
I dont understand why the duplex mode is fixed up after comparing for speed. I've added pseudo line numbers to point to the lines I don't understand.
The correct register is read in line 0004.
Then in line 0005 I see ''if( regValue & PHY_Configured_Speed)''.
It seems to me this should read ''if( regValue & PHY_Configured_Duplex)''.
Does anyone have an explanation or is this an error?
Regards
Hugh
if(ENET_OperatingMode == AUTO_NEGOTIATION)
{
/* The Link Status bit is a Latching High bit, so we need to read twice to get the real value */
0000 ENET_MIIReadReg (PHY_ADDRESS, PHY_XSR);
/* We wait for linked satus... */
0001 while( !(ENET_MIIReadReg (PHY_ADDRESS, PHY_XSR) & PHY_Linked_Status) );
/* Enable Auto-Negotiation */
0002 ENET_MIIWriteReg (PHY_ADDRESS, PHY_XCR, PHY_AutoNegotiation);
/* Wait until the autonegotiation will be completed */
0003 while( !(ENET_MIIReadReg (PHY_ADDRESS, PHY_XSR) & PHY_AutoNego_Complete) );
/* Read the result of the autonegotiation */
0004 regValue = ENET_MIIReadReg (PHY_ADDRESS, PHY_XCIIS);
/* */
0005 if( regValue & PHY_Configured_Speed)
{
ENET_MAC->MCR |=ENET_MCR_FDM; /* Full Duplex Mode */
ENET_MAC->MCR &=~ENET_MCR_DRO; /* Enable frame reception during transmission */
}
else
{
ENET_MAC->MCR &=~ENET_MCR_FDM; /* Half Duplex Mode */
ENET_MAC->MCR |=ENET_MCR_DRO; /* Disable frame reception during transmission */
}
}
