Flow Control
BCM5718 Programmer’s Guide
Broadcom
®
January 29, 2016 • 5718-PG108-R
Page 227
Flow Control Initialization Pseudocode
//Check the Link State
If (MII_Status_Reg.Link_Status == TRUE) Then
{
//Check PHY status register for full-duplex configuration
If (MII_Aux_Status_Reg.Auto_Neg_HCD ==
(1000_FULL_DUPLEX Or 100_FULL_DUPLEX Or 10_FULL_DUPLEX) ) Then
{
//Check if USER has forced either auto-negotiation or auto-advertise
If ( (Driver_Auto_Neg_Variable == ENABLED) And
(Driver_Auto_Advertise_Variable != FORCED_SPEED_DUPLEX )) Then
{
// Probe Phy control registers for advertised flow control info
// Expected abilities should match the configured abilities. Expected abilities
// are based on the IEEE 803.3ab flow control subsection.
If ( (Auto_Neg_Advertise_Reg.Asymetric_Pause != 802.3ab_Table_28B-3 ) And
(Auto_Neg_Advertise_Reg.Pause_Capable != 802.3ab_Table_28B-3 ) ) Then
{
//The current advertised state does not match 802.3 specifications
Driver_ Link__link_state = LINK_STATUS_DOWN
}
Else
{
If (Auto_Neg_Advertise_Reg.Pause_Capable == ENABLED)
{
If ( Auto_Neg_Advertise_Reg.Asymetric_Pause == ENABLED) ) Then
{
If (Auto_Neg_Link_Partner_Ability_Reg.Pause_Capable == ENABLED) Then
{
Driver_Flow_Capability = FLOW_CONTROL_TRANSMIT_PAUSE \
| FLOW_CONTROL_RECEIVE_PAUSE
}
Else If (Auto_Neg_Link_Partner_Ability_Reg.Asymetric_Pause == \
ENABLED) Then
{
Driver_Flow_Capability = FLOW_CONTROL_RECEIVE_PAUSE
}
Else
{
Driver_Flow_Capability = NONE
}
}
//The local physical layer was not configured to advertise Asymmetric pause
Else
{
If (Auto_Neg_Link_Partner_Ability_Reg.Pause_Capable == ENABLED) Then
{
Driver_Flow_Capability = FLOW_CONTROL_TRANSMIT_PAUSE \
| FLOW_CONTROL_RECEIVE_PAUSE
}
Else
{
Driver_Flow_Capability = NONE
}
}
}
// The local physical layer was not configured to advertise Pause capability