| ??? 02/17/09 19:52 Read: times |
#162529 - It's not that simple Responding to: ???'s previous message |
Andy Peters said:
Richard Erlacher said:
I need to move a large burst (~500 Mbytes) of serial (not ASYNC-formatted) data that arrives at a steady synchronous rate of ~10 Mbits/second into a PC from an 085x-based piece of hardware. These bursts cannot be interrupted, but are quite infrequent (~ one such burst per hour). 10 Mb/s is a puny data rate. I've got a Medium Camera Link set-up here that's doing 320 MB/s (that's capital B for bytes, four bytes per clock at 80 MHz). SCSI 320 can do that, too. USB is clearly ruled out because of its intermittent interaction with Windows. LOL, that's ridiculous. Use isochronous transfers using high-speed USB 2.0. Iso transfers guarantee bandwidth. The one thing I've repeatedly encountered is that Windows "goes away" during lengthy USB transfers, and does it for extended periods sometimes in excess of half a minute. The obvious thing to do is to avoid Windows or any other OS that can/will interrupt my transfer. Fortunately, DOS can be inhibited from doing that stuff, and the DMA transfer will keep the memory refreshed. -a It sounds simple, but since I'd be limited to the driver software the USB interface mfg has provided, inasmuch as I want to get the job done within this lifetime, writing an isochronous mode driver for it is out of the question. I could investigate the SCSI channel, since I do use those from time to time. The DOS approach will probably work best. RE |
