On Sat, Jul 26, 2008 at 1:40 PM, Petri Helenius <[EMAIL PROTECTED]> wrote: > William Herrin wrote: >> But cards like the Intel Pro/1000 have 64k of memory for buffering >> packets, both in and out. Few have very much more than 64k. 64k means >> 32k to tx and 32k to rx. Means you darn well better generate an >> interrupt when you get near 16k so that you don't fill the buffer >> before the 16k you generated the interrupt for has been cleared. Means >> you're generating an interrupt at least for every 10 or so 1500 byte >> packets. >> > > This is not true in the bus master dma mode how the cards are usually used. > The mentioned memory is used only as temporary storage until the card can > DMA the data into the buffers in main memory. Most Pro/1000 cards have > buffering capability up to 4096 frames.
Pete, I'll confess to some ignorance here. We're at the edge of my skill set. The pro/1000 does not need to generate an interrupt in order to start a DMA transfer? Can you refer me to some documents which explain in detail how a card on the bus sets up a DMA transfer? Thanks, Bill -- William D. Herrin ................ [EMAIL PROTECTED] [EMAIL PROTECTED] 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004
