Agree on all points.
Jim
Jim,
I said earlier “you”and I should have said “we”…
Yes, these issues will go through changes and false starts.
May need to disable most IRQ lines in the beginning.
Yes, and my sheet is going to have issues. I got to thinking later that I did not label the I2C clock as a CLK. Have not gone back to look yet.
I like and agree with what Burns said, once we get this all working we probably will not have to touch it any more. Temperature testing will be needed to be sure things work properly.
We may also find the pull-up they have on chip is not enough and have to add a pull-up or pull down to the board. I think I have most of them covered but may have missed something.
On the lines going to the PC104 I don’t know what is really going to be needed there without a lot more study on the interface. So i just made them inputs mostly to be safe. These lines should all be buffered but I did not want to add the additional chips and current. Careful coordination with others should be the solution but a lot of work there. We can address it later. I think the main goal is to get the CPU working and then test the radios, clock, and WDT etc.
I’ll look at the 570 data sheet and see what it says about pullup resistance.
An input can be configured with either a pullup, pulldown or nothing.
Want to start a group pool to bet on how many iterations it will take to get the configuration correct?
Not that difficult but easy to loose ones place going between your pin chart and the HCG settings.
Yes need to be sure the pull ups are enabled on these IRQ lines which will be inputs.
Ok to have pull ups on all inputs. If we have a problem meeting the Vol input level we can disable later.
Pull-ups are probably a high resistance, maybe 100K?
I have several external pull ups and a few pull downs.
POR could be a special case but we can start with pull-up.
You should double check this but I seem to remember that the internal pull-up/downs only work for INPUTS. Not sure if for example they would work on i2c. FWIW
In the last column labeled Pullup/Down does “Add on chip pullup” mean set the pullup with the HCG configuration?
My assumption is yes but wanted to crosscheck before defining.
The configurator assigns a pullup to all inputs by default.
If not required I assumption they will need to be manually reset in HCG.
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