Announcements
IMPORTANT: Cypress Developer Community currently doesn’t allow sign-in to prepare for the upcoming transition. To learn more, check out our announcement.
cancel
Showing results for 
Search instead for 
Did you mean: 

PSoC 5, 3 & 1

drmi_4295866
New Contributor

Hello all,

I am toggling one pin in psoc 5lp. In while loop I am write pin 1 and 0 after 1 ms delay. My question is that whenever my pin goes low to high or high to low it's generate ramp/slop (some delay exact 2.4 us) to toggle. In my pin setting slew rate is fast, Drive mode is strong drive. Even as per document, I read it's only take some nanoseconds then why it's take these much time? How can I remove? Is there any other settings in pins properties or any special pins for that?

Here is my code

While(1)

{

            Pin 0 Write(!(pin 0 Read()));

            Delay(1ms);

}

0 Likes
1 Solution
odissey1
Honored Contributor II

drmi,

The rise/fall time on digital pins should be in ns range. Take look at this video

C++ vs Assembly vs Verilog. on Vimeo

It also depends on the bandwidth of the scope and quality of the probe. On 100 MHz Tek scope equipjed with cheap $10 probes I see >100ns risetime. Same scope with homemade 1/20 probe shows  ~10ns risetime. Google how to make own probe with 1k resistor for fast signal fronts

Other simple steps is to add a load resistor to the pin (~1k) and switch probe to x10.

/odissey1

View solution in original post

0 Likes
2 Replies
brockr0-S
New Contributor II

Are you using the CY8CKIT-059?

Seven pins on that board have capacitors connected to them: P0[2,3,4], P3[2], P15[2,3,4]

odissey1 made a nice annotation kit that also serves as a handy reference if this is the problem.

KIT-059: annotation component for CY8CKIT-059 PSoC5LP Prototyping Kit

0 Likes
odissey1
Honored Contributor II

drmi,

The rise/fall time on digital pins should be in ns range. Take look at this video

C++ vs Assembly vs Verilog. on Vimeo

It also depends on the bandwidth of the scope and quality of the probe. On 100 MHz Tek scope equipjed with cheap $10 probes I see >100ns risetime. Same scope with homemade 1/20 probe shows  ~10ns risetime. Google how to make own probe with 1k resistor for fast signal fronts

Other simple steps is to add a load resistor to the pin (~1k) and switch probe to x10.

/odissey1

View solution in original post

0 Likes