--- crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68
On Mon, Jul 18, 2016 at 10:10 PM, Manuel A. Fernandez Montecelo <[email protected]> wrote: > 2016-07-18 20:57 Luke Kenneth Casson Leighton: >>> >>> I suppose that using custom co-processors/accelerators is an alternative >>> possibility for video/display, but probably not easy. Some uses of the >>> SoC (e.g. micro-servers) probably don't care anyway, >> >> >> yeah they wouldn't. that U500 would actually make a great EOMA200 >> processor. >> >>> but I understand >>> that it's part of the EOMA68 standard. >> >> >> it's not that, it's that the power requirements to run a separate >> video IC are just as heavy if not heavier than the actual processor >> itself. even just running the PCIe lanes between the video and main >> processor - driving the voltages up and down - can take up a >> significant proportion of the EOMA68 power budget. > > > Yeah, got that. > > What I meant is that even if many people who would use it as a > micro-server wouldn't be worried about the lack of video acceleration, > it always was (AFAIK) a hard requirement for the EOMA68 standard itself > -- being able to render video at FullHD or similar. nono, not at all, that's a misunderstanding: the actual requirement is about the maximum resolution that the LCD interface has to be driven at (1366x768 for type II 5mm cards, 1920x1080 for type I 3.3mm cards). an FPGA-based card using a zynq 7030 could do 18-bit or just 15-bit RGB/TTL and not have any kind of acceleration at all. there's even an ATSAM4 that operates at only 200 mhz which has an RGB/TTL interface: that would qualify... it's just that pricing is completely mad (somewhere around $9!) so it's not financially viable or justifiable. the IC1t was *barely* able to drive 1024x768 16bpp @ 50hz due to the internal memory bandwidth: amazingly they used the OpenCores LCD/VGA library but they didn't update its memory bandwidth. they were only expecting people to run it @ 640x480 @ 32bpp, or at most 800x600 @ 24bpp, but because the OpenCores VGA driver is publicly documented i was able to work out how to put it into 8-bit mode (2 bits red, 3 bits green, 3 bits blue) and because of the reduced internal bus bandwidth of dropping to one byte per pixel i was actually able to drive all the way up to 1440x900! there is even a monochrome mode but i didn't investigate that. so yeah, point is: Full HD (or any kind of 2D or 3D or Video acceleration at all) is *not* part of the EOMA68 hardware standard. at some point i really want to do an Ingenic M150 EOMA68 card and see how low the BOM can really be pushed. it'll be a 2-layer PCB (!) because the M150 is designed for 2-layer. their EVB is postage-stamp-sized, it's pretty amazing. l. _______________________________________________ arm-netbook mailing list [email protected] http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook Send large attachments to [email protected]
