You are here

Multiple drivers for GPIO ports (Hardware and Software) | Cypress Semiconductor

Multiple drivers for GPIO ports (Hardware and Software)

Summary: 3 Replies, Latest post by danaaknight on 17 Sep 2014 06:33 PM PDT
Verified Answers: 0
Last post
Log in to post new comments.
vasanthrs's picture
5 posts

 Hello everyone, I have been doing some basic PSOC4 programmes and I found that when I am driving same GPIO pin(RGB LED) using a hardware connection and using API of the pin , once the API is used the Hardware drivig is not working properly.


For example if i am turning on the led by giving it as the output of a PWM module. And once I give LED_Write(0); API ,the led doesn't turn ON even if the hardware output becomes 0. This happens once i use the API before that it is working properly. Can any one explain why this happens?


thank you

user_1377889's picture
9244 posts

Have a look into the PSoC4 TRM capture 7. here to explain the structure of the pins.

So, what would you perform, which of the two sources shal "win"m the port written or the digital signal? What do you expect to happen when they are different?



user_78878863's picture
2551 posts

I think whats happeneing is that LED_Write() sets the IO-Matrix so that the pin is used as GPIO, and not as fixed-function output anymore. That means that the PWM has no access to it anymore.

If you want to force LED to an on-state via API, use the stop/kill functionality of the PWM. (together with inverted outputs)

user_14586677's picture
7646 posts

You can look at the module .lst file and determine what the function actually

does. Not too difficult for simple components.


Regards, Dana.

Log in to post new comments.