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LAUNCHXL-F28P55X: Understanding the CLB Counter - Maybe a bug

Marco Noll
Prodigy 40 points
Part Number: LAUNCHXL-F28P55X

Tool/software:

I use the syscfg tool of CCS 20.2

I have a hard time understanding the counter behaviour. In the tool the configuration parameters are Reset, Event Trigger, Counter Enable and Direction.
In the code this correlates to Reset, Event Trigger, Mode_0 and Mode_1

It appears that When Enable is set, the counter counts with sys-clock rate as long as Enable input equals one. Thus Event Trigger has only effect when Enable is set to zero

Setting counter event action to 'add' and an event load value and an event trigger will cause the value to load,, though the event action is set to add. 
In fact none of the Counter event Actions changes any of the counter config values. This looks like a bug in the configuration tool. Unfortunately I did not find any documentation on the actual register. Can you post how the actual settings work without the tool, then it would be easier to analyze such issues.

Thanks,

  • 0
    Prodigy 40 points

    Answering my own question after watching the behaviour with different settings:
    Reset whenever 1, keeps the counter in reset, no matter what other inputs are. Straight forward and as somewhere mentioned in the Documentation
    Event process the event action on rising edge of the configured signal (this is independent of the enable setting or status)
    Enable when one or configured input is 1, counter counts with around 100MHz (why not 150?) frequency in whatever direction is set. 

    When the Event is triggered
    Add/Substract adds or substracts the Event Load Value from the current counter value 
    Left/Right shift bitshifts the current counter value by Event Load Value amount of bits when the Event, it's a regular shift, no barrel shifting 

    What I didn't understand in the beginning was, that Event and Enable are two independent features.
    When I looked at the generated defines I also overlooked that Counter Event Actions are coded into the     TILEx_CFG_MISC_CONTROL value.