SPRUII0F May 2019 – June 2024 TMS320F28384D , TMS320F28384D-Q1 , TMS320F28384S , TMS320F28384S-Q1 , TMS320F28386D , TMS320F28386D-Q1 , TMS320F28386S , TMS320F28386S-Q1 , TMS320F28388D , TMS320F28388S
The transmit path functions include tasks that the MAC must perform to make the PHY to enter the LPI state. In the transmit path, the software must set the LPIEN bit of the MAC_LPI_Control_Status register to indicate to the MAC to stop transmission and initiate the LPI protocol. The MAC completes the transmission in progress, generates the transmission status, and starts transmitting the LPI pattern instead of the IDLE pattern if the link status has been up continuously for a period specified in the LPI LS TIMER field of MAC_LPI_Control_Status register. The PHY Link Status bit of the LPI Control and Status Register indicates the link status of the PHY.
To make the PHY enter the LPI state, the MAC performs the following tasks:
To bring the PHY out of the LPI state, that is, when the software resets the LPIEN bit, the MAC performs the following tasks:
Figure 43-17 shows the behavior of TX_EN, TX_ER, and TXD[3:0] signals during the LPI mode transitions.