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Altera_Forum
Honored Contributor
13 years agoaltera tse mac signal ff_tx_rdy
Hi I am using tse mac ip for ethernet and i am getting rx side of sop & eop properly but i am getting the ff_tx_rdy low. when rx side of sop is always low & eop is properly getting in ...
Altera_Forum
Honored Contributor
13 years ago --- Quote Start --- It looks like the transmit FIFO gets full and can't accept more data, that's why the ready signal becomes low. Now I don't know why the FIFO gets full and doesn't empty itself. Could you have a look at the signals between the MAC and the PHY? Is it trying to send anything? What kind of Ethernet link are you using? Is it full duplex? --- Quote End --- Thanks. the full flag is indeed high. We are using full duplex. PHY is Marvel 88E1111 gigabit. TSE MAc is instantiated in SGMII triple speed mode. This problem goes away when I loop the MAC ff_rx signals to the ff_tx signals and keep the ff_rx_rdy to high. It also goes away when I connect the tx signals to a packet generator within the same FPGA. When I open up the tx data signals, and take them to the FPGA pins, the tx ready goes low and fifo full flag goes high. Question: At reset, is there any recommended levels at which the tx input lines including the clk to be held at? Should I control the tx_clk and rx_clk in any way? currently it is connected to a free running 50 MHz.