FlexPWM capture

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

FlexPWM capture

716 Views
zcc890406
Contributor II

Hi sir,

      I am using  the function of FlexPWM capture about  MPC5643L and have some question about it.

      The CAVL0 and CAVL1 register  capture the same edge when they were congfigured rising edge. They were triggered at the same time, so  I cannot caculate the frequncy of singal. I canot find the reason about this question.

 

thank you for help.

Labels (1)
0 Kudos
1 Reply

588 Views
PetrS
NXP TechSupport
NXP TechSupport

Hi,

if both capture circuits are enabled they are not triggered at the same time. They will work together in a ping-pong style, so once input capture process is started the capture circuit 0 is first armed and when a capture event occurs, capture circuit 1 is armed, and so on depending the capture mode.

For sure you can get the same value in CVALx registers, but it should belongs to another PWM period. You can read the CVALxCYC register to distinguish between PWM cycles.

BR, Petr

0 Kudos