Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
11 years ago

Tse mac

I am using ALTERA tripple speed ethernet ip core.My question is:-If rx_section_empty has crossed its threshold value and not coming down,will TSE MAC keep on sending pause frames ?????
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
11 years ago

Thanks for Reply.

Further to our discussion ,First of all my ethernet speed is 100 Mbps and i have set the holdoff_quanta register to 0x006c and pause quanta value to 0xffff.So accoding to my understanding ALTERA MAC should send pause frames with pause quanta value 0xffff at every 552 us.I have used wireshark application to capture the ethernet frames and as per my observation MAC is sending pause frames if data availbale in rx_fifo is going up and downto rx_septy_value.But if rx_septy_value is not comming down then it is not sending pause frames as wireshark is not showing any pause frames.

Anyhow as per your advice i will try to play with holdoff_quanta value and let u know.

One more thing that i want to know:- As in your first reply you told:-you have used external fifos and generated pause frames by using XOFF pins available in ALTERA MAC.I want to know:-If i have to send continuos pause frames then for how much time i have to keep the signal asserted to xoff pin. For ex if want to send ten pause frames continuously then,do i have to keep the the signal asserted to xoff pin for ten clocks or something else.??????

Please reply me.