I use the Alchitry CU V2 board together with the IO board (also V2). I searched for a list that shows the connections between ICE40 pin and the 4 IO board connectors, but couldn’t find one. Moreover I could not deduce, how the 4 connectors are named / numbered. There is no marking on the Alchitry Cu board and a layout seems not to be available.
So it is hard to spot, which ICE40 pin connects to which function on the IO board (LED, switch, etc.).
Is such a list available, or is there a simple way to create such list?
Hello,
You can get the list by looking at the constraints file provided by Labs Io v2 constraints
In this file the pins are numbered according to the board’s connectors (bank A, bank B) which is good for Labs use.
However, if you need the FPGA’s pins for use in IceCube or other tool, you need to make Labs generate it by creating an empty project for Cu v2, then add Io constraints and generate.
Labs will build a constraint file with FPGA’s pins somewhere in the build directory.
It’s also worth mentioning that the mapping for Alchitry header to FPGA pin is on GitHub.
Looking at the board with the USB port on the left bank A is on the top and bank B is on the bottom. The numbers are pin numbers. Starting with 1 in the bottom left (with the board in the same orientation) then top left is 2, then bottom one over is 3, etc. In other words, rotate the schematic symbol 90 degrees CCW.
Thanks for your effort, but I have not found the right solution.
The schematic (alchitry_copper v2 from 8/3/2023) of the Cu shows 50pin connectors X3 (Bank A), X4 (Bank B), X5 (Bank C) and X6 (Bank D), while the schamatic of the IO (alchitry_io rev.2 from 10/26/2021) has connectors B1A, B1B, B1C B1D.
I assume that X3-Bank A connects to B1A, X4 to B1B, etc.
But what is still confusing is the ICE40 pin numbering in the schematic (A1, A2, … G1, etc.), which does not relate to the constraints file from GitHub, where the pins are numbered like A70, B70 etc. Such numbers cannot be found in neither schematic.
I’m a bit helpless. Maybe I just use the wrong schematics. I downloaded them from alchitry shop
Btw.: I use the ICEcube2 development environment.
You don’t have the correct Cu schematic, you need this one
The one you have is actually revision 2 of the Cu v1