Ed_N
Newbie level 1
Hi,
I have been working on a problem for days and I run out of ideas. I got an Atemga644PV with an external RTC clock (32kHz) on TOSC1 and 2 for async timer2. I use pcint21 to read (count) some impulses but the higher the signal the more the RTC is affected to the point of stoping working.
I have tried:
- JTAG disabled
- Capacitors on the xtal for 10pF and 22pF and no capacitors at all
I don´t know what else to try to be honest. I have run the test on other pcint and this does not happen. Also one curios thing, even if I disable the interrupts the problem persists. Any ideas?
Just banging my head against a brick wall here!
Fustrated Ed
Added after 36 minutes:
A quick update, I have lifted pin 24 (pcint21) from the board and apply a frequency signal to it. The problem stops!
However the input channel is externally pulled high so if it was any stray capacitance or crosstalk it would still be there whether pin 24 was connected or not right?
Could this be a bug on the IC?
I have been working on a problem for days and I run out of ideas. I got an Atemga644PV with an external RTC clock (32kHz) on TOSC1 and 2 for async timer2. I use pcint21 to read (count) some impulses but the higher the signal the more the RTC is affected to the point of stoping working.
I have tried:
- JTAG disabled
- Capacitors on the xtal for 10pF and 22pF and no capacitors at all
I don´t know what else to try to be honest. I have run the test on other pcint and this does not happen. Also one curios thing, even if I disable the interrupts the problem persists. Any ideas?
Just banging my head against a brick wall here!
Fustrated Ed
Added after 36 minutes:
A quick update, I have lifted pin 24 (pcint21) from the board and apply a frequency signal to it. The problem stops!
However the input channel is externally pulled high so if it was any stray capacitance or crosstalk it would still be there whether pin 24 was connected or not right?
Could this be a bug on the IC?
