Hi,
I use ATSAM7L128.
I use a PIOC output to drive a hardware item. I need this output to be low until software is initialized.
So I configure my output with :
#define PIN_CMDE_CHARGEcfg {1 << 15, AT91C_BASE_PIOC, AT91C_ID_PIOC, PIO_OUTPUT_0, PIO_DEFAULT}
I connect a 500kohm resistor to ground with PIO output, then I use a scope to look at signals and at startup, I see :
when power is up, output is low for 100ms, then high for 25ms, then low again, then my software begins to work.
I can't avoid (even with a main program which do nothing) the output to go high !!!!!
Have you an idea to help me ?
Thanks

hello,
there is no chance to change this behaviour.
after reset the internal pull-up is always active!

regards
gerhard

I have replaced the 400k resistor with a 10k resistor.
I notice now a small potential elevation of IO output (only 0.2V) which is ok for me.
So it works
Thanks

hello geroge,
your method works as long as the internal pull-up resistor isn't changing, but keep in mind the minimum and maximum values (see data sheet, dc characteristics, Pull-up Resistor).

regards
gerhard