Posted on May 17, 2011 at 10:19Hi, All.
I discovered a very strange behaviour while updating PWM.
Now in details:
Settings: autoswitch, sensor, voltage, 8-bit PWM mode. PWM is generated on odd MCOx channels only.
Problem: while continuously !!!DECREASING!!! MCPUH value PWM disappears on odd MCOx outputs until MCPUH gets stable value. On even MCOx outputs signal is stable. At the same time i have the same PWM on MCPWMW output. It looks always perfect. It means that problem is somewhere in pwm-manager block (and in my brain :) )
One more thing i don't understand.
The same mc settings. Outputs are on, MTC clock is off. MCPUH has value, let's say, 2 times lower than MCP0L (it means 50% duty cycle by edge-aligned mode). I have signal on some odd MCO output where PWM is generated. as far as MTC clock is off, there is logical 1 on this output. What do i do? Just switch MTC clock on. Theoretically on this output PWM should appear immediatelly. But it appears in some hundred millisec. I need PWM without any delay. Any update of MCPUH doesn't bring effect.
P.S.: Writing this post i have got an idea. If all pwm related registers have preload registers, it means they have to be updated everytime PWM update has occured. Am I right?
