PIC12f675 - Electronic Circuits Projects Diagrams Free

MERV · 9th December 2007, 05:35 PM

I'm using an MPLAB ICD2 and a 12f675 in a simple adc circuit. The adc has to read <0.9v on its input, to activate a relay. I used the templates from IDE lists etc, and assembled code without errors! However when I simulate it the run window loops arround to give the following error!
(CORE-E0002: Stack under flow error occurred from instruction at 0x000000)

I'm still learning with PIC's and used others without problems? -- can anyone
help me please, or help with assembly code! Regards Merv.

Pommie · 9th December 2007, 05:44 PM

If the stack under flows then you have a return where you shouldn't have. If you have a call in your code then it should be matched with a return. Post your code and I'm sure someone here will be able to point out your error.

Mike.
P.S. when you post code please put [code ] and [/code ] (without the spaces) before and after the code.

MERV · 9th December 2007, 06:20 PM

Thanks Mike, this is the file I'm working from.

;************************************************* *********************
; This file is a basic code template for object module code *
; generation on the PIC12F675. This file contains the *
; basic code building blocks to build upon. As a project minimum *
; the 12F675.lkr file will also be required for this file to *
; correctly build. The .lkr files are located in the MPLAB *
; directory. *
; *
; If interrupts are not used all code presented between the *
; code section "INT_VECTOR and code section "MAIN" can be removed. *
; In addition the variable assignments for 'w_temp' and *
; 'status_temp' can be removed. *
; *
; Refer to the MPASM User's Guide for additional information on *
; features of the assembler and linker (Document DS33014). *
; *
; Refer to the respective PIC data sheet for additional *
; information on the instruction set. *
; *
;************************************************* *********************
; *
; File name:
; Date: *
; File Version: *
; *
; Author: *
; Company: *
; *
; *
;************************************************* *********************
; *
; Files required: *
; 12F675.lkr *
; *
; *
;************************************************* *********************
; *
; Notes: *
; *
; *
; *
; *
;************************************************* *********************

list p=12f675 ; list directive to define processor
#include <p12f675.inc> ; processor specific variable definitions

errorlevel -302 ; suppress message 302 from list file
COUNT EQU 20H
__CONFIG _CP_OFF & _CPD_OFF & _BODEN_OFF & _MCLRE_ON & _WDT_OFF & _PWRTE_ON & _INTRC_OSC_NOCLKOUT

; '__CONFIG' directive is used to embed configuration word within .asm file.
; The lables following the directive are located in the respective .inc file.
; See data sheet for additional information on configuration word settings.

;================================================= =========================
;
; Register Definitions

;================================================= =========================

W EQU H'0000'
F EQU H'0001'

;----- Register Files------------------------------------------------------

INDF EQU H'0000'
TMR0 EQU H'0001'
PCL EQU H'0002'
STATUS EQU H'0003'
FSR EQU H'0004'
GPIO EQU H'0005'

PCLATH EQU H'000A'
INTCON EQU H'000B'
PIR1 EQU H'000C'

TMR1L EQU H'000E'
TMR1H EQU H'000F'
T1CON EQU H'0010'

CMCON EQU H'0019'

ADRESH EQU H'001E'
ADCON0 EQU H'001F'

OPTION_REG EQU H'0081'

TRISIO EQU H'0085'

PIE1 EQU H'008C'

PCON EQU H'008E'

OSCCAL EQU H'0090'

WPU EQU H'0095'
IOC EQU H'0096'
IOCB EQU H'0096'

VRCON EQU H'0099'
EEDATA EQU H'009A'
EEDAT EQU H'009A'
EEADR EQU H'009B'
EECON1 EQU H'009C'
EECON2 EQU H'009D'
ADRESL EQU H'009E'
ANSEL EQU H'009F'

;----- STATUS Bits --------------------------------------------------------

IRP EQU H'0007'
RP1 EQU H'0006'
RP0 EQU H'0005'
NOT_TO EQU H'0004'
NOT_PD EQU H'0003'
Z EQU H'0002'
DC EQU H'0001'
C EQU H'0000'

;----- GPIO Bits --------------------------------------------------------

GP5 EQU H'0005'
GPIO5 EQU H'0005'
GP4 EQU H'0004'
GPIO4 EQU H'0004'
GP3 EQU H'0003'
GPIO3 EQU H'0003'
GP2 EQU H'0002'
GPIO2 EQU H'0002'
GP1 EQU H'0001'
GPIO1 EQU H'0001'
GP0 EQU H'0000'
GPIO0 EQU H'0000'

;----- INTCON Bits --------------------------------------------------------

GIE EQU H'0007'
PEIE EQU H'0006'
T0IE EQU H'0005'
INTE EQU H'0004'
GPIE EQU H'0003'
T0IF EQU H'0002'
INTF EQU H'0001'
GPIF EQU H'0000'

;----- PIR1 Bits ----------------------------------------------------------

EEIF EQU H'0007'
ADIF EQU H'0006'
CMIF EQU H'0003'
T1IF EQU H'0000'
TMR1IF EQU H'0000'

;----- T1CON Bits ---------------------------------------------------------

TMR1GE EQU H'0006'
T1CKPS1 EQU H'0005'
T1CKPS0 EQU H'0004'
T1OSCEN EQU H'0003'
NOT_T1SYNC EQU H'0002'
TMR1CS EQU H'0001'
TMR1ON EQU H'0000'

;----- COMCON Bits --------------------------------------------------------

COUT EQU H'0006'
CINV EQU H'0004'
CIS EQU H'0003'
CM2 EQU H'0002'
CM1 EQU H'0001'
CM0 EQU H'0000'

;----- ADCON0 Bits --------------------------------------------------------

ADFM EQU H'0007'
VCFG EQU H'0006'
CHS1 EQU H'0003'
CHS0 EQU H'0002'
GO EQU H'0001'
NOT_DONE EQU H'0001'
GO_DONE EQU H'0001'
ADON EQU H'0000'

;----- OPTION Bits --------------------------------------------------------

NOT_GPPU EQU H'0007'
INTEDG EQU H'0006'
T0CS EQU H'0005'
T0SE EQU H'0004'
PSA EQU H'0003'
PS2 EQU H'0002'
PS1 EQU H'0001'
PS0 EQU H'0000'

;----- PIE1 Bits ----------------------------------------------------------

EEIE EQU H'0007'
ADIE EQU H'0006'
CMIE EQU H'0003'
T1IE EQU H'0000'
TMR1IE EQU H'0000'

;----- PCON Bits ----------------------------------------------------------

NOT_POR EQU H'0001'
NOT_BOD EQU H'0000'

;----- OSCCAL Bits --------------------------------------------------------

CAL5 EQU H'0007'
CAL4 EQU H'0006'
CAL3 EQU H'0005'
CAL2 EQU H'0004'
CAL1 EQU H'0003'
CAL0 EQU H'0002'

;----- IOCB Bits --------------------------------------------------------

IOCB5 EQU H'0005'
IOCB4 EQU H'0004'
IOCB3 EQU H'0003'
IOCB2 EQU H'0002'
IOCB1 EQU H'0001'
IOCB0 EQU H'0000'

;----- IOC Bits --------------------------------------------------------

IOC5 EQU H'0005'
IOC4 EQU H'0004'
IOC3 EQU H'0003'
IOC2 EQU H'0002'
IOC1 EQU H'0001'
IOC0 EQU H'0000'

;----- VRCON Bits ---------------------------------------------------------

VREN EQU H'0007'
VRR EQU H'0005'
VR3 EQU H'0003'
VR2 EQU H'0002'
VR1 EQU H'0001'
VR0 EQU H'0000'

;----- EECON1 Bits --------------------------------------------------------

WRERR EQU H'0003'
WREN EQU H'0002'
WR EQU H'0001'
RD EQU H'0000'

;----- ANSEL Bits ---------------------------------------------------------

ADCS2 EQU H'0006'
ADCS1 EQU H'0005'
ADCS0 EQU H'0004'
ANS3 EQU H'0003'
ANS2 EQU H'0002'
ANS1 EQU H'0001'
ANS0 EQU H'0000'

;================================================= =========================
;
; RAM Definition
;
;================================================= =========================

__MAXRAM H'FF'
__BADRAM H'06'-H'09', H'0D', H'11'-H'18', H'1A'-H'1D', H'60'-H'7F'
__BADRAM H'86'-H'89', H'8D', H'8F', H'91'-H'94', H'97'-H'98', H'E0'-H'FF'
================================================== ========================

;===========================

;************************************************* *********************
RESET_VECTOR CODE 0x000 ; processor reset vector
goto main ; go to beginning of program

;INT_VECTOR CODE 0x004 ; interrupt vector location
; movwf w_temp ; save off current W register contents
; movf STATUS,w ; move status register into W register
; movwf status_temp ; save off contents of STATUS register

; isr code can go here or be located as a call subroutine elsewhere

; movf status_temp,w ; retrieve copy of STATUS register
; movwf STATUS ; restore pre-isr STATUS register contents
; swapf w_temp,f
; swapf w_temp,w ; restore pre-isr W register contents
; retfie ; return from interrupt

; these first 4 instructions are not required if the internal oscillator is not used
main
call 0x3FF ; retrieve factory calibration value
bsf STATUS,RP0 ; set file register bank to 1
movwf OSCCAL ; update register with factory cal value
bcf STATUS,RP0 ; set file register bank to 0

; remaining code goes here

++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++

BSF STATUS,RP0
MOVLW B'00111001'
MOVWF TRISIO

MOVLW B'00010001' ;SET UP ADC?
MOVWF ANSEL
MOVLW B'00000111'
MOVWF OPTION_REG

;CALL 3FFH
;MOVWF OSCCAL
;BCF STATUS,RP0
MOVLW B'00000111'
MOVWF CMCON

MOVLW B'10000001'
MOVWF ADCON0
CLRF GPIO

==================================
BEGIN BSF ADCON0,GO
WAIT BTFSC ADCON0,GO
GOTO WAIT
BSF STATUS,RP0
MOVF ADRESL,W
SUBLW .360
BTFSC STATUS,CARRY
BTSF GPIO,1
BTSF GPIO,2
initialize eeprom locations

;EE CODE 0x2100
; DE 0x00, 0x01, 0x02, 0x03
GOTO BEGIN

END ; directive 'end of program'

Pommie · 9th December 2007, 06:34 PM

Well, your code is hard to read as it is presented in such a huge manner. However, having stood back and looked at your code, I suspect there is a probable cause for your error. The end of your code doesn't stop. Try putting a goto $ at the end of your code. You should put this after the line BTSF GPIO,2. Actually, that isn't even a valid instruction.

Mike.

eng1 · 9th December 2007, 06:38 PM

Code:

 		;RESET_VECTOR	CODE	0x000		; processor reset vector
org 0x000
goto    main             ; go to beginning of program
 
 ;....


main

The CODE directive is generating that error in my opinion. Remove it and replace it with the org directive (see the above code).

Pommie · 9th December 2007, 06:46 PM

So, what does BTSF GPIO,1 do?

Mike.

eng1 · 9th December 2007, 06:58 PM

As you said, the code is very hard to read! honestly I haven't read the whole program.
I didn't see that error (we were posting at the same time, so I didn't read your reply, you're correct of course)

Other things to be checked: bank switching; registesr definitions are not necessary and might be an additional source of errors....

MERV · 9th December 2007, 07:01 PM

Quote:

Originally Posted by Pommie

Well, your code is hard to read as it is presented in such a huge manner. However, having stood back and looked at your code, I suspect there is a probable cause for your error. The end of your code doesn't stop. Try putting a goto $ at the end of your code. You should put this after the line BTSF GPIO,2. Actually, that isn't even a valid instruction.

Mike.

Many thanks, Sorry about the size!! I still have work to do on the code, so have been altering lines etc to overcome problem. The idea eventually will be to switch on a relay driven from GP1 when a dc voltage drops below 0.9v and switches the relay off above 1.8v. Quite simple -- but have not used this pic before. Many thanks.

wschroeder · 9th December 2007, 07:51 PM

Quote:

Originally Posted by Pommie

So, what does BTSF GPIO,1 do?

There will always be problems when you make up your own names for instructions ..

kchriste · 9th December 2007, 09:07 PM

I have edited your code so it will compile, but there are still issues with it. I suggest you only write 10 lines of code at a time before recompiling to eliminate being overwhelmed by errors. I didn't indent all the lines so you'll still get the " Found opcode in column 1. " warnings and I really don't know what you want to do with this line:

Code:

SUBLW .360

which gives the "Argument out of range. Least significant bits used." warning. I'll leave these for you to fix. The max size number you can handle at one time on a 8bit processor is 255 decimal.

Code:

	list p=12f675 ; list directive to define processor
	#include <p12f675.inc> ; processor specific variable definitions

	errorlevel -302 ; suppress message 302 from list file
COUNT EQU 20H
	__CONFIG _CP_OFF & _CPD_OFF & _BODEN_OFF & _MCLRE_ON & _WDT_OFF & _PWRTE_ON & _INTRC_OSC_NOCLKOUT

; '__CONFIG' directive is used to embed configuration word within .asm file.
; The lables following the directive are located in the respective .inc file.
; See data sheet for additional information on configuration word settings.





org 0x000 ; processor reset vector
goto main ; go to beginning of program


;INT_VECTOR CODE 0x004 ; interrupt vector location
; movwf w_temp ; save off current W register contents
; movf STATUS,w ; move status register into W register
; movwf status_temp ; save off contents of STATUS register


; isr code can go here or be located as a call subroutine elsewhere



; movf status_temp,w ; retrieve copy of STATUS register
; movwf STATUS ; restore pre-isr STATUS register contents
; swapf w_temp,f
; swapf w_temp,w ; restore pre-isr W register contents
; retfie ; return from interrupt


; these first 4 instructions are not required if the internal oscillator is not used
main
call 0x3FF ; retrieve factory calibration value
bsf STATUS,RP0 ; set file register bank to 1
movwf OSCCAL ; update register with factory cal value
bcf STATUS,RP0 ; set file register bank to 0


; remaining code goes here

;++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++


BSF STATUS,RP0
MOVLW B'00111001'
MOVWF TRISIO

MOVLW B'00010001' ;SET UP ADC?
MOVWF ANSEL
MOVLW B'00000111'
MOVWF OPTION_REG

;CALL 3FFH
;MOVWF OSCCAL
;BCF STATUS,RP0
MOVLW B'00000111'
MOVWF CMCON

MOVLW B'10000001'
MOVWF ADCON0
CLRF GPIO



;==================================
BEGIN BSF ADCON0,GO
WAIT BTFSC ADCON0,GO
	GOTO WAIT
BSF STATUS,RP0
MOVF ADRESL,W
SUBLW .360
BTFSC STATUS,C
BTFSc GPIO,1
BTFSc GPIO,2
;initialize eeprom locations

;EE CODE 0x2100
; DE 0x00, 0x01, 0x02, 0x03
	GOTO BEGIN

END ; directive 'end of program'

MERV · 9th December 2007, 09:13 PM

I'ts a typing error, strange the assembler has not spotted it though! This is the first time I've used this pic and MPLAB IDE for assembly code and simulation. I have tested other projects without problems -- it may my code in setting he PIC correctly? Kind regards. Merv

MERV · 9th December 2007, 09:24 PM

Hi, Many thanks for your help. My error btsf -- bsf should be of course.Excuse my ignorance, I thought this pic had a ten bit adc, and able to handle larger number values? As I mentioned new to using PIC's so probably trying to run before I can walk -- eeger to get projects up and running, so greatfull to you Guy's for all your assitance. Cheers Merv

eng1 · 9th December 2007, 10:08 PM

You have to take care of bank switching.

kchriste · 10th December 2007, 01:00 AM

Quote:

Originally Posted by MERV

I thought this pic had a ten bit adc, and able to handle larger number values?

Yes, the ADC can do 10bit resolution, but the data is put into two 8bit registers called, ADRESH and ADRESL (Read them as AD RESults High and Low). The PIC CPU can only deal with 8bit numbers natively; to handle 10 or 16bit numbers you must write code to handle it. You do this by splitting the data into 8bit chunks.

Quote:

I'ts a typing error, strange the assembler has not spotted it though! This is the first time I've used this pic and MPLAB IDE for assembly code and simulation.

I'm sure the compiler has spotted it; you just don't know where to look. Even though the compiler gives you the green bar graph and the "build succeeded" message you need to look at the "output" screen. Click Window/Output after compiling to read all the warnings and error messages created when you compiled your code last. Double clicking an error message will take you directly to the spot in the code that caused the error message. Be aware that the first error message can be the cause of the following ones so it is best to fix the top error message and recompile before trying to figure out the rest.

futz · 10th December 2007, 01:05 AM

It's simple enough to make the code readable. Just put it inside code tags so it looks like the code block below. To use code tags, just click on # in the menu above the text entry box before pasting your code.

Of course since I repasted the already messed up post from above, the code has already lost all its formatting. That wouldn't happen on an original post.

Code:

;************************************************* *********************
; This file is a basic code template for object module code *
; generation on the PIC12F675. This file contains the *
; basic code building blocks to build upon. As a project minimum *
; the 12F675.lkr file will also be required for this file to *
; correctly build. The .lkr files are located in the MPLAB *
; directory. *
; *
; If interrupts are not used all code presented between the *
; code section "INT_VECTOR and code section "MAIN" can be removed. *
; In addition the variable assignments for 'w_temp' and *
; 'status_temp' can be removed. *
; *
; Refer to the MPASM User's Guide for additional information on *
; features of the assembler and linker (Document DS33014). *
; *
; Refer to the respective PIC data sheet for additional *
; information on the instruction set. *
; *
;************************************************* *********************
; *
; File name:
; Date: *
; File Version: *
; *
; Author: *
; Company: *
; *
; *
;************************************************* *********************
; *
; Files required: *
; 12F675.lkr *
; *
; *
;************************************************* *********************
; *
; Notes: *
; *
; *
; *
; *
;************************************************* *********************

list p=12f675 ; list directive to define processor
#include <p12f675.inc> ; processor specific variable definitions

errorlevel -302 ; suppress message 302 from list file
COUNT EQU 20H
__CONFIG _CP_OFF & _CPD_OFF & _BODEN_OFF & _MCLRE_ON & _WDT_OFF & _PWRTE_ON & _INTRC_OSC_NOCLKOUT

; '__CONFIG' directive is used to embed configuration word within .asm file.
; The lables following the directive are located in the respective .inc file.
; See data sheet for additional information on configuration word settings.




;================================================= =========================
;
; Register Definitions

;================================================= =========================

W EQU H'0000'
F EQU H'0001'

;----- Register Files------------------------------------------------------

INDF EQU H'0000'
TMR0 EQU H'0001'
PCL EQU H'0002'
STATUS EQU H'0003'
FSR EQU H'0004'
GPIO EQU H'0005'

PCLATH EQU H'000A'
INTCON EQU H'000B'
PIR1 EQU H'000C'

TMR1L EQU H'000E'
TMR1H EQU H'000F'
T1CON EQU H'0010'

CMCON EQU H'0019'

ADRESH EQU H'001E'
ADCON0 EQU H'001F'


OPTION_REG EQU H'0081'

TRISIO EQU H'0085'

PIE1 EQU H'008C'

PCON EQU H'008E'

OSCCAL EQU H'0090'

WPU EQU H'0095'
IOC EQU H'0096'
IOCB EQU H'0096'

VRCON EQU H'0099'
EEDATA EQU H'009A'
EEDAT EQU H'009A'
EEADR EQU H'009B'
EECON1 EQU H'009C'
EECON2 EQU H'009D'
ADRESL EQU H'009E'
ANSEL EQU H'009F'


;----- STATUS Bits --------------------------------------------------------

IRP EQU H'0007'
RP1 EQU H'0006'
RP0 EQU H'0005'
NOT_TO EQU H'0004'
NOT_PD EQU H'0003'
Z EQU H'0002'
DC EQU H'0001'
C EQU H'0000'

;----- GPIO Bits --------------------------------------------------------

GP5 EQU H'0005'
GPIO5 EQU H'0005'
GP4 EQU H'0004'
GPIO4 EQU H'0004'
GP3 EQU H'0003'
GPIO3 EQU H'0003'
GP2 EQU H'0002'
GPIO2 EQU H'0002'
GP1 EQU H'0001'
GPIO1 EQU H'0001'
GP0 EQU H'0000'
GPIO0 EQU H'0000'

;----- INTCON Bits --------------------------------------------------------

GIE EQU H'0007'
PEIE EQU H'0006'
T0IE EQU H'0005'
INTE EQU H'0004'
GPIE EQU H'0003'
T0IF EQU H'0002'
INTF EQU H'0001'
GPIF EQU H'0000'

;----- PIR1 Bits ----------------------------------------------------------

EEIF EQU H'0007'
ADIF EQU H'0006'
CMIF EQU H'0003'
T1IF EQU H'0000'
TMR1IF EQU H'0000'

;----- T1CON Bits ---------------------------------------------------------

TMR1GE EQU H'0006'
T1CKPS1 EQU H'0005'
T1CKPS0 EQU H'0004'
T1OSCEN EQU H'0003'
NOT_T1SYNC EQU H'0002'
TMR1CS EQU H'0001'
TMR1ON EQU H'0000'

;----- COMCON Bits --------------------------------------------------------

COUT EQU H'0006'
CINV EQU H'0004'
CIS EQU H'0003'
CM2 EQU H'0002'
CM1 EQU H'0001'
CM0 EQU H'0000'

;----- ADCON0 Bits --------------------------------------------------------

ADFM EQU H'0007'
VCFG EQU H'0006'
CHS1 EQU H'0003'
CHS0 EQU H'0002'
GO EQU H'0001'
NOT_DONE EQU H'0001'
GO_DONE EQU H'0001'
ADON EQU H'0000'

;----- OPTION Bits --------------------------------------------------------

NOT_GPPU EQU H'0007'
INTEDG EQU H'0006'
T0CS EQU H'0005'
T0SE EQU H'0004'
PSA EQU H'0003'
PS2 EQU H'0002'
PS1 EQU H'0001'
PS0 EQU H'0000'

;----- PIE1 Bits ----------------------------------------------------------

EEIE EQU H'0007'
ADIE EQU H'0006'
CMIE EQU H'0003'
T1IE EQU H'0000'
TMR1IE EQU H'0000'

;----- PCON Bits ----------------------------------------------------------

NOT_POR EQU H'0001'
NOT_BOD EQU H'0000'

;----- OSCCAL Bits --------------------------------------------------------

CAL5 EQU H'0007'
CAL4 EQU H'0006'
CAL3 EQU H'0005'
CAL2 EQU H'0004'
CAL1 EQU H'0003'
CAL0 EQU H'0002'

;----- IOCB Bits --------------------------------------------------------

IOCB5 EQU H'0005'
IOCB4 EQU H'0004'
IOCB3 EQU H'0003'
IOCB2 EQU H'0002'
IOCB1 EQU H'0001'
IOCB0 EQU H'0000'

;----- IOC Bits --------------------------------------------------------

IOC5 EQU H'0005'
IOC4 EQU H'0004'
IOC3 EQU H'0003'
IOC2 EQU H'0002'
IOC1 EQU H'0001'
IOC0 EQU H'0000'

;----- VRCON Bits ---------------------------------------------------------

VREN EQU H'0007'
VRR EQU H'0005'
VR3 EQU H'0003'
VR2 EQU H'0002'
VR1 EQU H'0001'
VR0 EQU H'0000'

;----- EECON1 Bits --------------------------------------------------------

WRERR EQU H'0003'
WREN EQU H'0002'
WR EQU H'0001'
RD EQU H'0000'

;----- ANSEL Bits ---------------------------------------------------------

ADCS2 EQU H'0006'
ADCS1 EQU H'0005'
ADCS0 EQU H'0004'
ANS3 EQU H'0003'
ANS2 EQU H'0002'
ANS1 EQU H'0001'
ANS0 EQU H'0000'

;================================================= =========================
;
; RAM Definition
;
;================================================= =========================

__MAXRAM H'FF'
__BADRAM H'06'-H'09', H'0D', H'11'-H'18', H'1A'-H'1D', H'60'-H'7F'
__BADRAM H'86'-H'89', H'8D', H'8F', H'91'-H'94', H'97'-H'98', H'E0'-H'FF'
================================================== ========================

;===========================


;************************************************* *********************
RESET_VECTOR CODE 0x000 ; processor reset vector
goto main ; go to beginning of program


;INT_VECTOR CODE 0x004 ; interrupt vector location
; movwf w_temp ; save off current W register contents
; movf STATUS,w ; move status register into W register
; movwf status_temp ; save off contents of STATUS register


; isr code can go here or be located as a call subroutine elsewhere



; movf status_temp,w ; retrieve copy of STATUS register
; movwf STATUS ; restore pre-isr STATUS register contents
; swapf w_temp,f
; swapf w_temp,w ; restore pre-isr W register contents
; retfie ; return from interrupt


; these first 4 instructions are not required if the internal oscillator is not used
main
call 0x3FF ; retrieve factory calibration value
bsf STATUS,RP0 ; set file register bank to 1
movwf OSCCAL ; update register with factory cal value
bcf STATUS,RP0 ; set file register bank to 0


; remaining code goes here

++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++


BSF STATUS,RP0
MOVLW B'00111001'
MOVWF TRISIO

MOVLW B'00010001' ;SET UP ADC?
MOVWF ANSEL
MOVLW B'00000111'
MOVWF OPTION_REG

;CALL 3FFH
;MOVWF OSCCAL
;BCF STATUS,RP0
MOVLW B'00000111'
MOVWF CMCON

MOVLW B'10000001'
MOVWF ADCON0
CLRF GPIO



==================================
BEGIN BSF ADCON0,GO
WAIT BTFSC ADCON0,GO
GOTO WAIT
BSF STATUS,RP0
MOVF ADRESL,W
SUBLW .360
BTFSC STATUS,CARRY
BTSF GPIO,1
BTSF GPIO,2
initialize eeprom locations

;EE CODE 0x2100
; DE 0x00, 0x01, 0x02, 0x03
GOTO BEGIN

END ; directive 'end of program'

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9th December 2007, 05:35 PM	(permalink)
MERV	PIC12f675 I'm using an MPLAB ICD2 and a 12f675 in a simple adc circuit. The adc has to read <0.9v on its input, to activate a relay. I used the templates from IDE lists etc, and assembled code without errors! However when I simulate it the run window loops arround to give the following error! (CORE-E0002: Stack under flow error occurred from instruction at 0x000000) I'm still learning with PIC's and used others without problems? -- can anyone help me please, or help with assembly code! Regards Merv.

9th December 2007, 05:44 PM	(permalink)
Pommie	If the stack under flows then you have a return where you shouldn't have. If you have a call in your code then it should be matched with a return. Post your code and I'm sure someone here will be able to point out your error. Mike. P.S. when you post code please put [code ] and [/code ] (without the spaces) before and after the code.

9th December 2007, 06:20 PM	(permalink)
MERV	12f675 adc circuit problems. Thanks Mike, this is the file I'm working from. ;*********************************************** ******************* ; This file is a basic code template for object module code * ; generation on the PIC12F675. This file contains the * ; basic code building blocks to build upon. As a project minimum * ; the 12F675.lkr file will also be required for this file to * ; correctly build. The .lkr files are located in the MPLAB * ; directory. * ; * ; If interrupts are not used all code presented between the * ; code section "INT_VECTOR and code section "MAIN" can be removed. * ; In addition the variable assignments for 'w_temp' and * ; 'status_temp' can be removed. * ; * ; Refer to the MPASM User's Guide for additional information on * ; features of the assembler and linker (Document DS33014). * ; * ; Refer to the respective PIC data sheet for additional * ; information on the instruction set. * ; * ;*********************************************** ******************* ; * ; File name: ; Date: * ; File Version: * ; * ; Author: * ; Company: * ; * ; * ;*********************************************** ******************* ; * ; Files required: * ; 12F675.lkr * ; * ; * ;*********************************************** ******************* ; * ; Notes: * ; * ; * ; * ; * ;*********************************************** ***************** list p=12f675 ; list directive to define processor #include <p12f675.inc> ; processor specific variable definitions errorlevel -302 ; suppress message 302 from list file COUNT EQU 20H __CONFIG _CP_OFF & _CPD_OFF & _BODEN_OFF & _MCLRE_ON & _WDT_OFF & _PWRTE_ON & _INTRC_OSC_NOCLKOUT ; '__CONFIG' directive is used to embed configuration word within .asm file. ; The lables following the directive are located in the respective .inc file. ; See data sheet for additional information on configuration word settings. ;================================================= ========================= ; ; Register Definitions ;================================================= ========================= W EQU H'0000' F EQU H'0001' ;----- Register Files------------------------------------------------------ INDF EQU H'0000' TMR0 EQU H'0001' PCL EQU H'0002' STATUS EQU H'0003' FSR EQU H'0004' GPIO EQU H'0005' PCLATH EQU H'000A' INTCON EQU H'000B' PIR1 EQU H'000C' TMR1L EQU H'000E' TMR1H EQU H'000F' T1CON EQU H'0010' CMCON EQU H'0019' ADRESH EQU H'001E' ADCON0 EQU H'001F' OPTION_REG EQU H'0081' TRISIO EQU H'0085' PIE1 EQU H'008C' PCON EQU H'008E' OSCCAL EQU H'0090' WPU EQU H'0095' IOC EQU H'0096' IOCB EQU H'0096' VRCON EQU H'0099' EEDATA EQU H'009A' EEDAT EQU H'009A' EEADR EQU H'009B' EECON1 EQU H'009C' EECON2 EQU H'009D' ADRESL EQU H'009E' ANSEL EQU H'009F' ;----- STATUS Bits -------------------------------------------------------- IRP EQU H'0007' RP1 EQU H'0006' RP0 EQU H'0005' NOT_TO EQU H'0004' NOT_PD EQU H'0003' Z EQU H'0002' DC EQU H'0001' C EQU H'0000' ;----- GPIO Bits -------------------------------------------------------- GP5 EQU H'0005' GPIO5 EQU H'0005' GP4 EQU H'0004' GPIO4 EQU H'0004' GP3 EQU H'0003' GPIO3 EQU H'0003' GP2 EQU H'0002' GPIO2 EQU H'0002' GP1 EQU H'0001' GPIO1 EQU H'0001' GP0 EQU H'0000' GPIO0 EQU H'0000' ;----- INTCON Bits -------------------------------------------------------- GIE EQU H'0007' PEIE EQU H'0006' T0IE EQU H'0005' INTE EQU H'0004' GPIE EQU H'0003' T0IF EQU H'0002' INTF EQU H'0001' GPIF EQU H'0000' ;----- PIR1 Bits ---------------------------------------------------------- EEIF EQU H'0007' ADIF EQU H'0006' CMIF EQU H'0003' T1IF EQU H'0000' TMR1IF EQU H'0000' ;----- T1CON Bits --------------------------------------------------------- TMR1GE EQU H'0006' T1CKPS1 EQU H'0005' T1CKPS0 EQU H'0004' T1OSCEN EQU H'0003' NOT_T1SYNC EQU H'0002' TMR1CS EQU H'0001' TMR1ON EQU H'0000' ;----- COMCON Bits -------------------------------------------------------- COUT EQU H'0006' CINV EQU H'0004' CIS EQU H'0003' CM2 EQU H'0002' CM1 EQU H'0001' CM0 EQU H'0000' ;----- ADCON0 Bits -------------------------------------------------------- ADFM EQU H'0007' VCFG EQU H'0006' CHS1 EQU H'0003' CHS0 EQU H'0002' GO EQU H'0001' NOT_DONE EQU H'0001' GO_DONE EQU H'0001' ADON EQU H'0000' ;----- OPTION Bits -------------------------------------------------------- NOT_GPPU EQU H'0007' INTEDG EQU H'0006' T0CS EQU H'0005' T0SE EQU H'0004' PSA EQU H'0003' PS2 EQU H'0002' PS1 EQU H'0001' PS0 EQU H'0000' ;----- PIE1 Bits ---------------------------------------------------------- EEIE EQU H'0007' ADIE EQU H'0006' CMIE EQU H'0003' T1IE EQU H'0000' TMR1IE EQU H'0000' ;----- PCON Bits ---------------------------------------------------------- NOT_POR EQU H'0001' NOT_BOD EQU H'0000' ;----- OSCCAL Bits -------------------------------------------------------- CAL5 EQU H'0007' CAL4 EQU H'0006' CAL3 EQU H'0005' CAL2 EQU H'0004' CAL1 EQU H'0003' CAL0 EQU H'0002' ;----- IOCB Bits -------------------------------------------------------- IOCB5 EQU H'0005' IOCB4 EQU H'0004' IOCB3 EQU H'0003' IOCB2 EQU H'0002' IOCB1 EQU H'0001' IOCB0 EQU H'0000' ;----- IOC Bits -------------------------------------------------------- IOC5 EQU H'0005' IOC4 EQU H'0004' IOC3 EQU H'0003' IOC2 EQU H'0002' IOC1 EQU H'0001' IOC0 EQU H'0000' ;----- VRCON Bits --------------------------------------------------------- VREN EQU H'0007' VRR EQU H'0005' VR3 EQU H'0003' VR2 EQU H'0002' VR1 EQU H'0001' VR0 EQU H'0000' ;----- EECON1 Bits -------------------------------------------------------- WRERR EQU H'0003' WREN EQU H'0002' WR EQU H'0001' RD EQU H'0000' ;----- ANSEL Bits --------------------------------------------------------- ADCS2 EQU H'0006' ADCS1 EQU H'0005' ADCS0 EQU H'0004' ANS3 EQU H'0003' ANS2 EQU H'0002' ANS1 EQU H'0001' ANS0 EQU H'0000' ;================================================= ========================= ; ; RAM Definition ; ;================================================= ========================= __MAXRAM H'FF' __BADRAM H'06'-H'09', H'0D', H'11'-H'18', H'1A'-H'1D', H'60'-H'7F' __BADRAM H'86'-H'89', H'8D', H'8F', H'91'-H'94', H'97'-H'98', H'E0'-H'FF' ================================================== ======================== ;=========================== ;********************************************* ******************* RESET_VECTOR CODE 0x000 ; processor reset vector goto main ; go to beginning of program ;INT_VECTOR CODE 0x004 ; interrupt vector location ; movwf w_temp ; save off current W register contents ; movf STATUS,w ; move status register into W register ; movwf status_temp ; save off contents of STATUS register ; isr code can go here or be located as a call subroutine elsewhere ; movf status_temp,w ; retrieve copy of STATUS register ; movwf STATUS ; restore pre-isr STATUS register contents ; swapf w_temp,f ; swapf w_temp,w ; restore pre-isr W register contents ; retfie ; return from interrupt ; these first 4 instructions are not required if the internal oscillator is not used main call 0x3FF ; retrieve factory calibration value bsf STATUS,RP0 ; set file register bank to 1 movwf OSCCAL ; update register with factory cal value bcf STATUS,RP0 ; set file register bank to 0 ; remaining code goes here ++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++ BSF STATUS,RP0 MOVLW B'00111001' MOVWF TRISIO MOVLW B'00010001' ;SET UP ADC? MOVWF ANSEL MOVLW B'00000111' MOVWF OPTION_REG ;CALL 3FFH ;MOVWF OSCCAL ;BCF STATUS,RP0 MOVLW B'00000111' MOVWF CMCON MOVLW B'10000001' MOVWF ADCON0 CLRF GPIO ================================== BEGIN BSF ADCON0,GO WAIT BTFSC ADCON0,GO GOTO WAIT BSF STATUS,RP0 MOVF ADRESL,W SUBLW .360 BTFSC STATUS,CARRY BTSF GPIO,1 BTSF GPIO,2 initialize eeprom locations ;EE CODE 0x2100 ; DE 0x00, 0x01, 0x02, 0x03 GOTO BEGIN END ; directive 'end of program'

9th December 2007, 06:34 PM	(permalink)
Pommie	Well, your code is hard to read as it is presented in such a huge manner. However, having stood back and looked at your code, I suspect there is a probable cause for your error. The end of your code doesn't stop. Try putting a goto $ at the end of your code. You should put this after the line BTSF GPIO,2. Actually, that isn't even a valid instruction. Mike.

9th December 2007, 06:38 PM	(permalink)
eng1	Code: ;RESET_VECTOR CODE 0x000 ; processor reset vector org 0x000 goto main ; go to beginning of program ;.... main The CODE directive is generating that error in my opinion. Remove it and replace it with the org directive (see the above code).

9th December 2007, 06:46 PM	(permalink)
Pommie	So, what does BTSF GPIO,1 do? Mike.

9th December 2007, 06:58 PM	(permalink)
eng1	As you said, the code is very hard to read! honestly I haven't read the whole program. I didn't see that error (we were posting at the same time, so I didn't read your reply, you're correct of course) Other things to be checked: bank switching; registesr definitions are not necessary and might be an additional source of errors.... Last edited by eng1; 9th December 2007 at 07:07 PM.

9th December 2007, 09:13 PM	(permalink)
MERV	I'ts a typing error, strange the assembler has not spotted it though! This is the first time I've used this pic and MPLAB IDE for assembly code and simulation. I have tested other projects without problems -- it may my code in setting he PIC correctly? Kind regards. Merv

9th December 2007, 09:24 PM	(permalink)
MERV	Hi, Many thanks for your help. My error btsf -- bsf should be of course.Excuse my ignorance, I thought this pic had a ten bit adc, and able to handle larger number values? As I mentioned new to using PIC's so probably trying to run before I can walk -- eeger to get projects up and running, so greatfull to you Guy's for all your assitance. Cheers Merv

9th December 2007, 10:08 PM	(permalink)
eng1	You have to take care of bank switching.