SPRUJ17H March 2022 – October 2024 AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1
On the MII transmit ports, there is a multiplexer for each MII transmit port that enables selection of either the transmit data from the PRUs or from the RX MII interface of the other MII interface. Figure 7-78 shows a simple diagram of PRU transmit multiplexer.
The transmit multiplexers enable the PRU-ICSS to either operate in a bypass mode where the PRU is not involved in processing MII traffic or use of one of the PRU cores for transmitting data into the MII interface. There are two instances of the TX MII multiplexer and the select lines for each TX multiplexer are provided by the PRU-ICSS programmable registers (MII_RT_TXCFG0/1[8] TX_MUX_SELn, where n = 0 or 1). The select lines are common between register and FIFO interface. It is expected that the select lines will not change during the course of a frame so that can avoid data exchange error.