Clock frequency for uClinux?

[Altera_Forum]

I was just wondering what frequency is typically used/required for uClinux running on a Cyclone? I ask because I'm running into some problems with networking running at 66 MHz. I'm finding that usign an Opencores MAC, I am getting TX Buffer overruns - this is on custom hardware. It happens when I try to cat a large file using telnet for example... things like FTP and HTTPD seem to work ok though. I tried the same setup on an EP1C12_eval board, and it did the same thing more or less.. 

 I am using an initramfs kernel, sothe filesystem is readily available in SDRAM... One interesting thing is that when I use the eval board and actually mount the filesystem in flash as root, it doesn't happen - one theory would be since it's not available as fast in Flash, it won't overrun the TX Buffers. But when it's in RAM, filesystem data is available a lot faster, so it has the potential to overrun maybe?? If I increase the frequency on the eval board 72Mhz, it doesn't happen - I can't do this on my custom hardware since I can't get the fmax that high.  What do you guys typically use?

[Altera_Forum]

--- Quote Start ---  originally posted by jdhar@Dec 4 2005, 12:51 PM i was just wondering what frequency is typically used/required for uclinux running on a cyclone? i ask because i&#39;m running into some problems with networking running at 66 mhz. i&#39;m finding that usign an opencores mac, i am getting tx buffer overruns - this is on custom hardware. it happens when i try to cat a large file using telnet for example... things like ftp and httpd seem to work ok though. i tried the same setup on an ep1c12_eval board, and it did the same thing more or less..  i am using an initramfs kernel, sothe filesystem is readily available in sdram... one interesting thing is that when i use the eval board and actually mount the filesystem in flash as root, it doesn&#39;t happen - one theory would be since it&#39;s not available as fast in flash, it won&#39;t overrun the tx buffers. but when it&#39;s in ram, filesystem data is available a lot faster, so it has the potential to overrun maybe?? if i increase the frequency on the eval board 72mhz, it doesn&#39;t happen - i can&#39;t do this on my custom hardware since i can&#39;t get the fmax that high.  what do you guys typically use? <div align='right'><{post_snapback}> (index.php?act=findpost&pid=11318)  --- quote end ---    --- Quote End ---    nm... figured it out - had to change the read size and write size http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/smile.gif