--- crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68
On Thu, Jan 12, 2017 at 8:50 AM, Tor, the Marqueteur Marqueteur@fineartmarquetry.com wrote:
EOMA50 would be better for it, but something like a digital audio player might like an OS tailored to understand its buttons, and the card with that OS installed on it might be a bit screwy to use for a laptop (or phone). Nevertheless, IIUC, as long as nothing will blow up, and you get some semblance of usable output, it's still OK by the standard.
pretty much.... yyeah. examples include the passthrough card that i quickly designed a couple of weeks ago: i connected an STM32F072's SPI pins to the EOMA68 SDMMC, because it's _barely_ compliant... if you want 4-pin you can do bit-banging.... which willl be horribly slow on a 72mhz Cortex M0 especially given that the STM32F072's USB bus is USB 1.1 (11mbit/sec) but that's not a problem as far as the *standard* is concerned.
other examples include the (failed, sadly) IC1t which used the opencores.org vga controller (yes, really!) and the bandwidth was so limited on the framebuffer "reader" (wishbone bus, 16-bit-wide) that if you wanted 1366x768 you had to do it as monochrome (!)... but, again, that's *not* a problem as far as the *standard* is concerned. in the strictest sense, it can achieve 1366x768 output... just with only black/white.
another is the jz4775 which has 2 USB interfaces - one of them is USB 1.1: again, not a problem: it'll work... just.
so there's lots of flexibility: any one SoC needs to comply with the absolute bare minimum, so that if people *really want* to pay only $11 for a Card they can, and if they want better they can pay $150 for an RK3288 with 4GB RAM and 32GB ultra-fast eMMC.
l.