I got hard-reset problem for my board with two XS1-L16-128. Here is the symptom:
* Unplug/Plug:
--- If the board is unplugged for a long time--- Plug-in will start the program successfully
--- If the board is plugged for long time----------Unplug and Plug-in quickly will NOT start the program.
* Keep the board plugged, and pull down/up the RESET pin:
--- If the RESET pin is kept low for <200ms-------------the board starts running successfully
--- If the RESET pin is kept low for 200ms~300ms----the board may or may-not run(probability)
--- If the RESET pin is kept low for >300ms-------------the board fails to run
Anybody has some hints on this issue? Thanks!
* I copied most of the design from sliceKit board.
* I check signals of MODE3, MODE2, DEBUG, RESET on oscilloscope, all seems fine!
Hard reset problem (board with two XS1-L16-128)
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jerryXCORE
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- Joined: Tue Apr 30, 2013 10:41 pm
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will1979
- Member
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The unplug/plug problem: do you have a bleeder resistor on your power supply?
The long reset problem: The data sheet seems to suggest that the pins float whilst in reset, and that the links between the two chips may need external pull-downs?
The long reset problem: The data sheet seems to suggest that the pins float whilst in reset, and that the links between the two chips may need external pull-downs?
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jerryXCORE
- Experienced Member
- Posts: 65
- Joined: Tue Apr 30, 2013 10:41 pm
The unplug/plug problem: do you have a bleeder resistor on your power supply?
I do NOT have one, you think it is better to connect one bleeder resistor near power supply?
The long reset problem: The data sheet seems to suggest that the pins float whilst in reset, and that the links between the two chips may need external pull-downs?
which pins should be floated: MODE3? or else?
It might be difficult to add external pull-downs for links on my board, how important is it?
I do NOT have one, you think it is better to connect one bleeder resistor near power supply?
The long reset problem: The data sheet seems to suggest that the pins float whilst in reset, and that the links between the two chips may need external pull-downs?
which pins should be floated: MODE3? or else?
It might be difficult to add external pull-downs for links on my board, how important is it?
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will1979
- Member
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- Joined: Mon Oct 26, 2015 11:06 am
I don't think it matters where you put the bleeder resistor; anywhere will do. It just avoids the power supplies floating to an undesirable level whilst unplugged.
No need to float any pins; the chip however seems to float all IO pins during reset, which means that the link that the second chip uses for booting is in an undefined state and needs pull-downs to guarantee a '0' when reset is released.
No need to float any pins; the chip however seems to float all IO pins during reset, which means that the link that the second chip uses for booting is in an undefined state and needs pull-downs to guarantee a '0' when reset is released.
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jerryXCORE
- Experienced Member
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- Joined: Tue Apr 30, 2013 10:41 pm
Will, you are exactly right:
* I did NOT add a bleeder resistor.
* I added pull-down resistor on two of link-B pins (B0,B1), based on datasheet.
* And both hard-reset problems are solved!
Thanks so much!
* I did NOT add a bleeder resistor.
* I added pull-down resistor on two of link-B pins (B0,B1), based on datasheet.
* And both hard-reset problems are solved!
Thanks so much!