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snow
Joined: 28 Jun 2005
Posts: 200
Location: Ashburton / Mid Canterbury / New Zealand
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 Posted: Fri Jan 24, 2020 2:07 am Post subject: Reset micro command |
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Top of the morning to you all.
This is bound to be a no brainer... Whats the code for resetting a micro? At the moment I'm starting the watchdog timer and letting it fail causing the micro to restart.
There's bound to be a more more elegant way of doing it i have come across yet
Thanks
Snow
(BASCOM-AVR version : 2.0.8.2 ) |
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Paulvk
Joined: 28 Jul 2006
Posts: 1257
Location: SYDNEY
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| Posted: Fri Jan 24, 2020 3:18 am Post subject: |
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This will cause it to reboot but not the same as re-set pin
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JC
Joined: 15 Dec 2007
Posts: 586
Location: Cleveland, OH
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| Posted: Fri Jan 24, 2020 4:01 am Post subject: |
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I guess it depends upon what you need to accomplish.
I think the following is true, but I'm certainly open to hearing other thoughts.
For a "true" Reset, setting the Watchdog is the typical approach.
One could also use a "spare" I/O pin to trigger the Reset\ pin, perhaps through an RC combo.
Note that the above will:
Reset the micro.
Set all I/O pins to Input mode.
Reset the clock to the default, (Xmega, and possibly O-Series, but I haven't used the O-series yet).
Validate the Power On Reset control logic's signal to "start" the micro running again.
Trash variables.
If you just do a manual jump to the prog Org, it isn't clear to me that any of the above takes place, except for the SW manually reconfiguring the I/O pins, and re-initializing variables that you take the time to do within your SW.
JC |
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snow
Joined: 28 Jun 2005
Posts: 200
Location: Ashburton / Mid Canterbury / New Zealand
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| Posted: Fri Jan 24, 2020 10:47 am Post subject: |
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Hi JC.
I'm wanting to do a "Clean Boot Up" as if the power has been cycled basically.
Thanks |
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MWS
Joined: 22 Aug 2009
Posts: 2262
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| Posted: Fri Jan 24, 2020 8:14 pm Post subject: |
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| Paulvk wrote: | This will cause it to reboot but not the same as re-set pin
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Reboot by chance maybe.
It may work if you use a bootloader, as it can jump to the bootloader-start then, if not it jumps into empty space or executes invalid opcode. |
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JC
Joined: 15 Dec 2007
Posts: 586
Location: Cleveland, OH
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| Posted: Sat Jan 25, 2020 2:42 am Post subject: |
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| Quote: | | I'm wanting to do a "Clean Boot Up" as if the power has been cycled basically. |
Truly then, stick with the Watchdog timeout!
JC |
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snow
Joined: 28 Jun 2005
Posts: 200
Location: Ashburton / Mid Canterbury / New Zealand
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| Posted: Sat Jan 25, 2020 11:51 pm Post subject: |
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| Thanks people for your feedback |
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KenHorse
Joined: 16 Jul 2004
Posts: 523
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| Posted: Sat Mar 14, 2020 6:24 pm Post subject: |
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I must say that my experience with a watchdog reset versus a power cycle does not result in the same end.
For example, if I have corrupt variables (due to framesize, hwstack, etc) being overwritten, a watchdog reset doesn't fix it. Only a power cycle seems to. |
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MWS
Joined: 22 Aug 2009
Posts: 2262
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| Posted: Sun Mar 15, 2020 12:47 am Post subject: |
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| KenHorse wrote: | I must say that my experience with a watchdog reset versus a power cycle does not result in the same end.
For example, if I have corrupt variables (due to framesize, hwstack, etc) being overwritten, a watchdog reset doesn't fix it. Only a power cycle seems to. |
That's nonsense.
At startup a routine is executed, which clears SRam and sets the stack pointer, corrupt variables are gone then.
This startup happens even at soft reset via Goto 0, but sure as well at watchdog reset and power reset.
Defaults for all processor registers are however reset by watchdog and power reset only.
If you did experience anything different, then it's due to side effects, like hardware issues. |
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KenHorse
Joined: 16 Jul 2004
Posts: 523
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| Posted: Sun Mar 15, 2020 12:52 am Post subject: |
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| Only hardware (other than processor) that would be involved would be RS232 level shifter and +5 regulator and I've never heard of those needing a hard reset |
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MWS
Joined: 22 Aug 2009
Posts: 2262
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| Posted: Sun Mar 15, 2020 11:11 am Post subject: |
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| KenHorse wrote: | | Only hardware (other than processor) that would be involved would be RS232 level shifter and +5 regulator and I've never heard of those needing a hard reset |
Only because you did experience ambiguous problems which you've solved with a crowbar, it does not make your statement correct.
Be aware if you've used $NORAMCLEAR or $NOINIT without requirement, you did create the problem yourself.
You can check my statement with some simple code. At startup read the stack area, stack pointer and one timer register for example, print everything to UART.
Then recursively call 10 times a sub, which alters stack and stack pointer by saving return addresses, additional write to above timer register.
Activate the WD and wait for reset to happen, at restart you will notice stack pointer and stack area is reset to it's previous state and the timer register is at default too.
After you've found out my statement is correct, you don't need to confuse other readers anymore by doing generally false posts.
I do not doubt that your special circuit needed a power cycle, however I'd avoid voodoo and would check about the true culprit.
Btw., if you still have doubts for the controller it is a difference between WD-reset and hard reset, simply pull the controller's reset pin low.
If reset is not connected to anything else and pulling it leads to correct behavior of your circuit, then and only then you may have an odd behavior.
Microchip may be interested then. |
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hgrueneis
Joined: 04 Apr 2009
Posts: 902
Location: A-4786 Brunnenthal
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| Posted: Tue Mar 17, 2020 9:48 pm Post subject: |
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In the many years I have used Bascom (and asm) and used it for a variety of boards and applications, I have never ever needed to reset the processor.
If that is needed, then there is a major problem with the software. Even in loops where is a danger of getting stuck, there is always a solution to overcome the situation. In my programing there is never a part to reset the processor. Bad handling of errors might lead to it. But again "bad programing". So, if you need to reset your processor, check your bad programing. The only time you need to reset, is when you reprogram flash memory. I have been through many different programing languages and the same rule applies, check your own faults.
Maybe a harsh remark, but true.
Best regards
Hubert |
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KenHorse
Joined: 16 Jul 2004
Posts: 523
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| Posted: Tue Mar 17, 2020 10:05 pm Post subject: |
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| hgrueneis wrote: | In the many years I have used Bascom (and asm) and used it for a variety of boards and applications, I have never ever needed to reset the processor.
If that is needed, then there is a major problem with the software. Even in loops where is a danger of getting stuck, there is always a solution to overcome the situation. In my programing there is never a part to reset the processor. Bad handling of errors might lead to it. But again "bad programing". So, if you need to reset your processor, check your bad programing. The only time you need to reset, is when you reprogram flash memory. I have been through many different programing languages and the same rule applies, check your own faults.
Maybe a harsh remark, but true.
Best regards
Hubert |
In my application, a reset of the processor (M2561) is necessary after 4K of new data is loaded into ERAM so it is read into SRAM for runtime and pointers are cleared.
I suppose there are other ways to accomplish that but I don't see a reset as the easiest way (smallest compiled code option as well) as any sort of cardinal sin |
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MWS
Joined: 22 Aug 2009
Posts: 2262
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| Posted: Wed Mar 18, 2020 12:02 am Post subject: |
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| KenHorse wrote: | | I suppose there are other ways to accomplish that but I don't see a reset as the easiest way (smallest compiled code option as well) as any sort of cardinal sin |
My son, you are forgiven for writing weird code, but you shalt suffer your sins for posting nonsense because you do not understand the code you wrote.
| Quote: | | For example, if I have corrupt variables (due to framesize, hwstack, etc) being overwritten, a watchdog reset doesn't fix it. Only a power cycle seems to. |
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