On Fri, Apr 15, 2016 at 1:47 PM, Laxman Dewangan <ldewangan@xxxxxxxxxx> wrote: > On Friday 15 April 2016 04:45 PM, Linus Walleij wrote: >> On Fri, Apr 15, 2016 at 11:55 AM, Laxman Dewangan <ldewangan@xxxxxxxxxx> >> wrote: >> But to be sure we would like to know what is actually happening, >> electronically speaking, when you set this up. Do you have any >> idea? > > From electronic point of view, the value of VIL, VIH, VOL, VOH (Input/output > voltage level for low and high state) are different when talking for 0 t > 1.8V and 0 to 3.3V. Yeah that I get. But since it is switched on a per-pin basis, and this is not about what voltage is actually supplied to the I/O cell, because that comes from the outside, it is a mystery why it is even needed. I understand that there is a bit selecting driving voltage level in the register range, what I don't understand is what that is doing in the I/O cell. The bit in the register must be routed to somehing in the I/O cell and I would like to know what. I take it that an ordinary CMOS totem-pole push-pull output is going to work the same with 1.8 and 3.3V alike so it's obviously not enabling any extra transistors or anything. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
