Assumption is that VCC on the ICE40 is stiff 3.3V, even if I only can find VCC supplied with R100 (VCCPLL1 and VCCPLL0). VPP_2V5 is 3V3 via a zener. But there are several +3V3 in the diagram that may be connected to 3V3 power (like VCCIO and VCC_SPI). But there are no arrows to 3V3, just the name. Is this the drawing convention? (I guess so, because if not there would be very few connections to the outer world).
Are high pin output (unloaded) 3V3 or 2V5? I assume 3V3.
I see in the ICE40 data sheet that it has "Three High Current Drivers used for three different LEDs or one RGB LED". Are these any of the soldered LEDs? Which ones? The others? And how much is "high current"?
I cannot either find the driving capability of the I/O pins. I would so much like to drive 24 LEDs directly, active low, if only via a 1K (2-3mA). 24 buffers, of any sort, would take up so much space. I guess the IO pad has cmos, or would it have mosfets that virtually pull the lines to ground?
