Post by thread:[PIC]: BROWN OUT QUESTION

Can anybody help with a couple of questions: When should a brown out circuit be used.I understand that its needed if the psu droops but does this happen that often in reality? Also i assemble projects using mplab and include one of the standard header file(16f84a.inc).I always get a verify processor message even if i put a 'list' command at the top of the main program and an 'include' command.Is there any way of stopping these messages Many thanks Dave -- http://www.piclist.com hint: To leave the PICList spam_OUTpiclist-unsubscribe-requestTakeThisOuTmitvma.mit.edu

At 07:21 PM 10/3/01 +0100, you wrote: >Can anybody help with a couple of questions: >When should a brown out circuit be used.I understand that its needed if the psu >droops but does this happen that often in reality? Generally, every time it's turned off. That may not sound like much of a big deal, but if you have battery-backed RAM or EEPROM you may find the processor up to some serious mischief in the turn-off period. Another time can be the typical electrical system response to a short where it flickers and retrys (presumably hoping that Mr. Squirrel has been incinerated and sent to squirrel heaven, thus removing the short). This can cause an improper reset and then the operation from that point forward may be wrong. Or any other kind of flickering of the power. I've found it to be absolutely essential in many of my product designs to have a reliable brown-out circuit, and tend to use the external variety. Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" .....speffKILLspam@spam@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com /.-.\ (( * )) \\ // Please help if you can: \\\ dailynews.yahoo.com/fc/US/Emergency_Information/ //\\\ /// \\\ \/ \/ -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestKILLspammitvma.mit.edu

Dave Selvester wrote: > Also i assemble projects using mplab and include one of the standard header file(16f84a.inc).I always get a verify processor message even if i put a 'list' command at the top of the main program and an 'include' command.Is there any way of stopping these messages Select the same processor in the [Options -> Development Mode] menu item. -- Best regards Tony mICros http://www.bubblesoftonline.com .....salesKILLspam.....bubblesoftonline.com -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestspam_OUTTakeThisOuTmitvma.mit.edu

----- Original Message ----- From: Tony Nixon <Tony.Nixonspam_OUTENG.MONASH.EDU.AU> > > Also i assemble projects using mplab and include one of the standard header file(16f84a.inc).I always get a verify processor message even if i put a 'list' command at the top of the main program and an 'include' command.Is there any way of stopping these messages<< > > Select the same processor in the [Options -> Development Mode] menu > item. I have been finding that MPLAB likes to change my selection a LOT since I bought my ICD, it didn't do it so much in PIC Start Plus mode though. Jeff -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

On Thu, 4 Oct 2001 08:51:48 +1000 Tony Nixon <@spam@Tony.NixonKILLspamENG.MONASH.EDU.AU> wrote: > Dave Selvester wrote: > > > Also i assemble projects using mplab and include one of the standard header file(16f84a.inc).I always get a verify processor message even if i put a 'list' command at the top of the main program and an 'include' command.Is there any way of stopping these messages > > > Select the same processor in the [Options -> Development Mode] menu > item. > > -- Thanks for the advice Tony. I.m pretty sure the correct processor was set in options/development.I had a list and include command.It seems to pick up this indef statement from the pic16f84a.inc file.Im using Promate II,but cant see anything else i.m doing wrong.Would this possibly cause an error in my assembled code? {Quote hidden}> Best regards > > Tony > > mICros > http://www.bubblesoftonline.com > KILLspamsalesKILLspambubblesoftonline.com > > -- > http://www.piclist.com hint: To leave the PICList > RemoveMEpiclist-unsubscribe-requestTakeThisOuTmitvma.mit.edu > > > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Dave Selvester wrote: > > > > > > Select the same processor in the [Options -> Development Mode] menu > > item. > > > > -- > Thanks for the advice Tony. > I.m pretty sure the correct processor was set in options/development.I had a list and include command.It seems to pick up this indef statement from the pic16f84a.inc file.Im using Promate II,but cant see anything else i.m doing wrong.Would this possibly cause an error in my assembled code? It may, if warnings are generated like "Address exceeds maximum range for this processor". Check the command line statement which is shown prior to assembly. (Usually the screen that pops up when you press [ALT F10]. It will tell you the processor that the code is being assembled for. In your case, when the code is being assembled, MPASM is finding another processor defined in your code from the "list" directive. This error message is telling you that the assembler is ignoring the processor definition "in the code", and is using the one defined in the command line instead. I have just tested a code assmebly with 16F84A selected and using the 16F84A.inc file and I don't get any problems. -- Best regards Tony mICros http://www.bubblesoftonline.com spamBeGonesalesspamBeGonebubblesoftonline.com -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email TakeThisOuTlistservEraseMEspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body

Got it.It was a confusion using capital letters.I had converted the header files to small letters so it never understood my LIST command.I reloaded the original header file(In capitals)and modified my source code with the register names in capitals - Fine now I presume Everybody suffers from messages about page bank warnings? Is it just a case of including an 'errorlevel -302' statement. All the best and thanks again On Mon, 8 Oct 2001 09:06:37 +1000 Tony Nixon <RemoveMETony.NixonTakeThisOuTENG.MONASH.EDU.AU> wrote: {Quote hidden}> Dave Selvester wrote: > > > > > > > > > Select the same processor in the [Options -> Development Mode] menu > > > item. > > > > > > -- > > Thanks for the advice Tony. > > I.m pretty sure the correct processor was set in options/development.I had a list and include command.It seems to pick up this indef statement from the pic16f84a.inc file.Im using Promate II,but cant see anything else i.m doing wrong.Would this possibly cause an error in my assembled code? > > It may, if warnings are generated like "Address exceeds maximum range > for this processor". > > Check the command line statement which is shown prior to assembly. > (Usually the screen that pops up when you press [ALT F10]. It will tell > you the processor that the code is being assembled for. > > In your case, when the code is being assembled, MPASM is finding another > processor defined in your code from the "list" directive. This error > message is telling you that the assembler is ignoring the processor > definition "in the code", and is using the one defined in the command > line instead. > > I have just tested a code assmebly with 16F84A selected and using the > 16F84A.inc file and I don't get any problems. > > -- > Best regards > > Tony > > mICros > http://www.bubblesoftonline.com > salesEraseME.....bubblesoftonline.com > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email EraseMElistservmitvma.mit.edu with SET PICList DIGEST in the body > > > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Dave Selvester wrote: > >Got it.It was a confusion using capital letters.I had converted the header >files to small letters so it never understood my LIST command.I reloaded >the original header file(In capitals)and modified my source code with the >register names in capitals - Fine now > >I presume Everybody suffers from messages about page bank warnings? Is it >just a case of including an 'errorlevel -302' statement. > I'd suggest using the "errorlevel -302" only when you've actually switched over to the alternate registers. Doing alternate bank twiddling with the warning temporarily disabled is fine. Once you switch back to the normal registers, though, you may want to use an "errorlevel +302" to re-enable the warning for the rest of your program. Regards, Bob _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> I presume Everybody suffers from messages about page bank warnings? Yes, there are a bunch of warnings that are completely useless because they occur often or in legitimate code. > Is it just a case of including an 'errorlevel -302' statement. Yes. There are several such messages I always disable. I run the assembler from a wrapper (for other reasons) and have it filter out the useless messages while it's at it. ******************************************************************** Olin Lathrop, embedded systems consultant in Littleton Massachusetts (978) 742-9014, RemoveMEolinEraseMEEraseMEembedinc.com, http://www.embedinc.com -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

I prefer to never use the "errorlevel -302" at all. But rather do something like this: BN0 = 0 ; Starting address of each bank BN1 = 0x80 BN2 = 0x100 BN3 = 0x180 cblock 0x80+something ; variables in bank 1 a_var another_var endc cblock 0x100+whatever ; variables in bank 2 etc etc_2 endc Then later, down in my code: bsf STATUS,RP0 ; access bank 1 movf a_var^BN1,W bsf STATUS,RP1 bcf STATUS,RP0 ; access bank 2 addwf etc^BN2,W Bob Ammerman RAm Systems (contract development of high performance, high function, low-level software) {Original Message removed}

Perhaps with your experience Olin it makes sense to ignore these messages outright, however for newbies (or amatuers such as myself) it is necessary to check out those warnings from time to time. I have coded for PICs alot but from time to time I still goof on when I'm on the correct page (especially when dealing with multiple branches of code). I personally recommend for those who aren't as experienced as many on this list to use the condition disabling of these warnings. TTYL > {Original Message removed}

Bob Ammerman wrote: {Quote hidden}> >I prefer to never use the "errorlevel -302" at all. But rather do something >like this: > >BN0 = 0 ; Starting address of each bank >BN1 = 0x80 >BN2 = 0x100 >BN3 = 0x180 > > cblock 0x80+something ; variables in bank 1 > a_var > another_var > endc > > cblock 0x100+whatever ; variables in bank 2 > etc > etc_2 > endc > > >Then later, down in my code: > > bsf STATUS,RP0 ; access bank 1 > > movf a_var^BN1,W > > bsf STATUS,RP1 > bcf STATUS,RP0 ; access bank 2 > > addwf etc^BN2,W > I like that. :=) It looks like a great way to handle banked variables. I wondered how you were dealing with the defined register names until I just pulled up a '.inc' file. My 16F84.inc file defines the bank 1 registers as 0x8_ values. I presume that the XOR with BN1 will work with them just as well as it does with banked variables. Thanks for sharing this tip. Regards, Bob _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics