How to figure out why pins can't be connected to a given port? | Cypress Semiconductor
How to figure out why pins can't be connected to a given port?
I received a CY8CKit-049 http://www.cypress.com/?rID=92146 which I want to use to do the software developement prior to ordering the PCBs. I'm working on a project where the port mapping in PSoC Creator has been done and the PCB layout has finished, but not ordered yet.
So, I build the main circuit on a breadboard with the same port connections used in the finished design. While finishing the breadboard circuit I got the idea to use a display during software development. Since the Cypress provided LCD component doesn't allow to connect the LCD over multiple ports and I don't want to use the multiport LCD community component I decided to control the LCD by simple bit-banging and added the corresponding pins, three single output pins and a 4-bit wide IO pin.
Now, here comes the problem: PSoC Creator doesn't allow me to set the single pins to the remaining free port pins. Since PSoC Creator doesn't show why a pin can't be connected to a given port I don't have any idea how to solve it.
Some of the ports used in the end design required to use LVTTL input threshold. After setting the 4-bit IO pin to LVTTL threshold I was able to assign it to a free adjacent port portion, but it seems that this doesn't help for the single pins.
I still can change some of the pinport connections, but I'm interested why some connections are not allowed (would be nice if PSoC Creator has a list of 'unusable port for this pin because...' list) and how to figure it out. The current datasheet doesn't mention any side-effects or 'unusable' combinations, and the
I'll investigate further when I'm back in office tomorrow, but maybe someone can give me some hints. If needed I can provide the project files.