Post by thread:[PIC]: 16f871 assembler problems?? no support?? H

I've been working on a project using the 16F871 chip, I got two samples from Microchip, updated MPLAB to the latest version, and set to get going on this. The first thing I always do is something simple, just to let me know that the chip is working, rather than do something elaborate and try to figure out what I did wrong. So I did the simple, read a port switch, and turn on an LED when the switch activates. No go. I used portA for the input, set the TRIS to 0xFF, and used portC as the output, setting TRIS to 0x00 Seems the portC is not behaving as an output. I'm using a 4MHz TTL oscillator (yes its working, have it hooked to OSC1 input, and get an output on OSC2, input is set to HS. I even backed off and made the program simple by just TURNING on the LED but portC seems to be...not working or intializing. Now, one thing that is strange is I get the following error in MPLAP when I assemble. Building TEST.HEX... Compiling TEST.ASM: Command line: "C:\PROGRA~1\MPLAB\MPASMWIN.EXE /p16F871 /q D:\A_STC\TEST.ASM" Message[301] D:\A_STC\P16F871.INC 35 : MESSAGE: (Processor-header file mismatch. Verify selected processor.) Warning[224] D:\A_STC\TEST.ASM 19 : Use of this instruction is not recommended. Warning[224] D:\A_STC\TEST.ASM 22 : Use of this instruction is not recommended. Build completed successfully. Whats the deal with the processor header file mismatch? here is the source file list p=16F871 ; list directive to define processor #include <p16F871.inc> ; processor specific variable definitions PORTA EQU H'0005' PORTB EQU H'0006' PORTC EQU H'0007' PORTD EQU H'0008' PORTE EQU H'0009' PCLATH EQU H'000A' org 0x000 ; The main line code starts here main goto init org 0x010 init movlw 0xFF tris PORTA movlw 0x00 tris PORTC here bcf PORTC,2 bsf PORTC,0 bcf PORTC,1 bsf PORTC,2 nop nop nop goto here end ____________________________________________________________________ Get free email and a permanent address at http://www.netaddress.com/?N=1 -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! use spam_OUTlistservTakeThisOuTmitvma.mit.edu?bodyT%20PICList%20DIGEST

> > dont know never used them but l do know that microchip is fazing out the > tris command, > > try > > movlw 0xFF > movwf TRISA Some short notes. Make sure you correctly set the bank bit (RP1 I believe) because the TRIS registers are in the second ram bank. BTW this is the primary value of the TRIS instructions, they don't require changing banks back and forth to set the TRIS bits. Probably isn't a big deal unless you have a set of IO ports that flop back and forth from inputs to outputs. Also remember to reset the RP1 bit after you've done the move. And in your code below you should have at least one NOP between changes to the same port as the change actually doesn't happen until a cycle in the next instruction IIRC. The PORTA bits on the 16F87X chips pop up as analog inputs. So be sure to change those bits to digital inputs before you try to use them. Along those same lines you may want to triple check that PORTC isn't configured to something strange. And a special note on the 16F87X chips: if low voltage programming is enabled make sure the PORTB3 is strapped correctly otherwise the chip may wander into programming mode. The easiest way to alleviate this program is to set the chip is HVP mode only using the config bits. Hope this helps you get started. BAJ > > etc...making sure TRISA,B,C are defined properly to their correct register > addresses of course...l have always done it this way anyway, l could never > understand the TRIS command being there seems like a waste of time to > me...it does the same as movwf anyway...maybe they just wanted to fill a > spare hole in their command set ??? > > {Original Message removed}

With the header file mismatch, go into MPLAB, open options/development mode, then set the processor type for editor or sim (whatever you're using) to 16F871, I am sure you will find this is set to something else. Other wise check your p16F871.inc file to see if someone has edited it (never edit them). Good luck. Hardware Engineering wrote: {Quote hidden}> > I've been working on a project using the 16F871 chip, I got two samples from > Microchip, updated MPLAB to the latest version, and set to get going on this. > > The first thing I always do is something simple, just to let me know that the > chip is working, rather than do something elaborate and try to figure out what > I did wrong. So I did the simple, read a port switch, and turn on an LED when > the switch activates. No go. I used portA for the input, set the TRIS to > 0xFF, and used portC as the output, setting TRIS to 0x00 > > Seems the portC is not behaving as an output. I'm using a 4MHz TTL oscillator > (yes its working, have it hooked to OSC1 input, and get an output on OSC2, > input is set to HS. > > I even backed off and made the program simple by just TURNING on the LED but > portC seems to be...not working or intializing. > > Now, one thing that is strange is I get the following error in MPLAP when I > assemble. > > Building TEST.HEX... > > Compiling TEST.ASM: > Command line: "C:\PROGRA~1\MPLAB\MPASMWIN.EXE /p16F871 /q D:\A_STC\TEST.ASM" > Message[301] D:\A_STC\P16F871.INC 35 : MESSAGE: (Processor-header file > mismatch. Verify selected processor.) > Warning[224] D:\A_STC\TEST.ASM 19 : Use of this instruction is not > recommended. > Warning[224] D:\A_STC\TEST.ASM 22 : Use of this instruction is not > recommended. > > Build completed successfully. > > Whats the deal with the processor header file mismatch? > > here is the source file > > list p=16F871 ; list directive to define processor > #include <p16F871.inc> ; processor specific variable definitions > PORTA EQU H'0005' > PORTB EQU H'0006' > PORTC EQU H'0007' > PORTD EQU H'0008' > PORTE EQU H'0009' > PCLATH EQU H'000A' > > org 0x000 ; The main line code starts here > main > goto init > org 0x010 > init > movlw 0xFF > tris PORTA > > movlw 0x00 > tris PORTC > here > bcf PORTC,2 > bsf PORTC,0 > bcf PORTC,1 > bsf PORTC,2 > nop > nop > nop > goto here > > end > > ____________________________________________________________________ > Get free email and a permanent address at http://www.netaddress.com/?N=1 > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > use .....listservKILLspam@spam@mitvma.mit.edu?body -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! use listservKILLspammitvma.mit.edu?body=SET%20PICList%20DIGEST

>> list p=16F871 ; list directive to define processor #include <p16F871.inc> ; processor specific variable definitions PORTA EQU H'0005' PORTB EQU H'0006' PORTC EQU H'0007' PORTD EQU H'0008' PORTE EQU H'0009' PCLATH EQU H'000A' << Why are you manually trying to define the port registers? This is all done in the include file. That's part of its job. >> tris PORTA << Don't use TRIS. It is an old instruction that is not supposed to be used on this family, and isn't in the documentation for this processor. Do a MOVWF TRISA instead. Above all, read the manual. ***************************************************************** Olin Lathrop, embedded systems consultant in Devens Massachusetts (978) 772-3129, .....olinKILLspam.....cognivis.com, http://www.cognivis.com -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! use EraseMElistservspam_OUTTakeThisOuTmitvma.mit.edu?body=SET%20PICList%20DIGEST

On Thu, 28 Sep 2000 01:03:57 +1000, you wrote: >dont know never used them but l do know that microchip is fazing out the >tris command, > >try > >movlw 0xFF >movwf TRISA > >etc...making sure TRISA,B,C are defined properly to their correct register >addresses of course...l have always done it this way anyway, l could never >understand the TRIS command being there seems like a waste of time to >me...it does the same as movwf anyway...maybe they just wanted to fill a >spare hole in their command set ??? TRIS is very useful as it does not require page-select bits to be twiddled to access it. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! use listservspam_OUTmitvma.mit.edu?bodyT%20PICList%20DIGEST

as far as Processor-header mismatch you may have different MCU in emulator or simulator setup. Now back to portC. once similar thing happened with me and I found that portC bit 0 and 1 also has timer1 external OSC setup add this BCF T1CON,3 this will make sure timer1 is disabled. include file already has PORTA EQU 0x05 all that you do not need to type them again remove PORTA thru PCLATH. instead of > movlw 0xFF > tris PORTA use this movlw 0xFF movwf TRISA PORTC,2 will turn on and off too fast you can't see it unless you are using step by step. {Quote hidden}> here > bcf PORTC,2 > bsf PORTC,0 > bcf PORTC,1 > bsf PORTC,2 > nop > nop > nop > goto here I guess that is all for now since you didn't mention your name I do not know who you are. hope this helps Andre Abelian {Original Message removed}