Topic : Problem with One Pulse Function in ST7

Forum : ST7/STM8

Original Post
Post Information Post
July 15, 2011 - 10:58am
Guest

Hi,

I have a problem with the One Pulse Function of the ST7FLIT19BY1M6.

I initialized the Timer as described in the data sheet, but it looks like it does not work.
If there is no pulse on the LTIC pin, I should at least see the PWM3 pin go high every time the counter
reaches the auto reload value, am I right?

I also activated the overflow interrupt and used the ISR to set a pin high and low again. But it looks like
the ISR never gets called because the pin stays low all the time

I was wondering if the reason for this could be that I supply the micro with 3.3 volt and have a cpu
frequency of 8 MHz, as in the data sheet it says that this is at the border of guaranteed functionality..

Thanks in advance and kind regards,

enjo
Replies
Post Information Post
+1
0
-1
July 15, 2011 - 11:51am
Guest

I just changed the counter frequency from 32 MHz to fCPU and now it works.

So is the 3.3 volt supply voltage too low for operation with 32 MHz?

Kind regards,

enjo
+1
0
-1
July 15, 2011 - 1:04pm
Guest

Ok, I finally got the problem solved myself :)

I was always looking in the data sheet in the timer chapter for something i did wrong,
but the problem was that I didn't set the PLL32 bit in the option byte.

Bye :)

enjo
+1
0
-1
July 18, 2011 - 11:23am
Raisonance Support Team

Great!

"Auto-fix" features are always the best for us ;-)