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in PBP, CON is used to define a software constant, in asm it should looks like
YourConstantVariable = .25
or
#DEFINE YourConstantVariable .25
Using pre-defined constant here and there, allow to have a better readable code, and also allow to do some changes without having to scroll the whole code.
For a 12F675 asm example.. well, first google hit gave me
http://www.jbgizmo.com/page29.htm
Steve
It's not a bug, it's a random feature.
There's no problem, only learning opportunities.
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stack overflow
hi people,
has anyone ever encountered a problem of stack overflow in their program?
rite now im doing a program to transmit a stack of data which contain 16 bit + 64 bit +
and the pic that im using is a pic12f675. what should i do to reduce this error?
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Hi Medusa,
I had this problem once and it turned out to be a subroutine that had a GOTO at the end of it instead of RETURN. Changed the word--solved the problem.
HTH,
BobK
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thanks bobk..i tried that, put return at the end of each goto instruction i have, but still it has not succeeded. is it possible due to overflow stack?
my program is supposed to have a stack of 8 byte output excluding the preamble and header and timeguard.
does anyone ever write a program that has a subroutine as follows
read input from port GPIO
move data from GPIO to 'input' register
take only data from bit 1
store the input (bit 1)to bit 0 at another register
repeat for eight times
what i already have in mind
movfw GPIO
movwf input
movlw 0000 0000
xorwf input,f
goto rotate
rotate
rrf input,f
rrf input,f
anyone has any idea to continue?
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Hi Medusa,
That's not what I meant. If you are calling a subroutine then at the end of the subroutine you put a RETURN. GOTO does not go at the end of a subroutine. This was the problem I had with one of my projects (18F452). The stack overflow was causing my project to hangup when it got to the subroutine after the stack overflowed. This was the only point I was trying to make.
If you have both a GOTO and a RETURN then you might still be experiencing a problem.
HTH,
BobK
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need help
Hi Bruce!
I have tried ur codes on RfPIC kit. i can see the data being sent by transmitter on GP2 and received on PORTC.1 on receiver side but the LED's are not blinking. what might be the problem.plz help me troubleshoot.
thanks
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That's hard to say. It works perfectly on my rfRXD0420 module installed in PICkit 1 board.
Are you compiling the receiver code without any changes, and programming it into a
PIC16F676 on the PICKit 1 board with the rfRXD0420 installed per the instructions?
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Hi
U have not included modedefs.bas in ur program.is that an issue?
I did that but to no avail.
maybe config fuses are causing something.they seem ok.they are as under when i read them using PICkit 1 software:
12F675
config word:0x31D4
osccal: 0x3480
bandgap: 0x3000
12F676
config word:0x31C4
osccal: 0x3440
bandgap: 0x3000
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rfrxd0420
Hi there,
I've altered the receiver_demo program to suit my application. - I took in the data from rfRxd0420 drom RC2 and try to take it out serially from RC0 of the pic16f676 so that I can
probe the data transmitted.
Currently, I'm simulating the program using MPLAB IDE. Pardon me if I'm wrong.
The receive_demo program that I understand, will check for header. But,
it does says that if the data is high before 6ms, therefore the header is valid.
What if the data is also 'LOW'?
I'm actually having problems with simulation coz it does not want to
come out of the loop - unless I put '1' in between.
When it came out of the loop, I should be able to record that and then output that
to the RC0 but it seems that the program didn't even jump to search for a guard time,
instead it continue the process to find for high or low pulse.
I just altered the receive demo of the dev kit. Can anyone help me please?
Or do you suggest a better way to simulate this program?
MAIN
call CLOCK ; to update TRMLOW and TMRHIGH
; TMRLOW ~=4us TMRHIGH ~=1ms
movlw HIGH STATEM
movwf PCLATH
movf STATECNTR, W ; Mask out the high order bits of
andlw B'00001111' ; STATECNTR (a noise guard)
addwf PCL, F ; The program clock (PCL) is incre-
STATEM
; check for possible start of data stream
goto BEGIN ; mented by STATECNTR in order
goto BEGIN1 ; to go to the appropiate routine
goto HEADER ; header is being ignored
goto HEADER1 ; just count up the time and then takes the data
goto HIGHPLSE ; times the width of Hi Pulse
goto LOWPULSE
goto RECORD ; record the 8 byte data
goto WAIT4END ; wait for guard time to be greater than 8ms
goto FIRST0 ; check whether DATA0 of bit 0 is 0 or 1
call SENDOUT ; to send out the serial data out through portc pin 0
goto RESET ; These RESET commands correct
goto RESET ; erroneous values of STATECNTR
goto RESET ; not caught by the mask above.
goto RESET
goto RESET
goto RESET
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from the demo program, they used ASK modulation which use NRZ format modulation.
in this format, when the input is zero it would give you a pulse of 110 while if the input is one, it would give pulse 011, which means it will still give you pulse high for whichever input.
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im still experiencing this overflow stack error message..
ive tried to change all goto to call instruction
put return for every subroutine..but still it doesnot work
can anyone help me
i pasted my full program below
Code:;nur azrin hilmi ;gdp 17-telemetr LIST P=RF675K ; list directive to define processor #include <RF675K.INC> ; processor specific variable definitions ;**************define variables********************************* #define sensor GPIO, 1 #define txd GPIO, 2 ; (Output) Transmit Data #define pb3 GPIO, 3 ; (Input Only) Push button switch GP3 #define pb4 GPIO, 4 ; (Input) Push button switch GP4 #define rfena GPIO, 5 ; (Output) RF Enable ; GPIO Pins = xx543210 ; #define gptris b'00011011' #define TGUARD d'5' #define exor b'00000000' #define total d'8' ; #define rtime d'5' ;*************************************************************** org 0x00 goto initialize org 0x004 movwf w_temp swapf STATUS,W bcf STATUS, 5 ;select bank 0 movwf status_temp ;save status register ;*************************************************************** ; interrupt service routine (ISR) ; interrupt on change on pin of gpio movfw GPIO bcf INTCON,0 ;************************************************************** swapf status_temp,w ;set bank into original state movwf STATUS swapf w_temp,F swapf w_temp,W retfie ;*************************************************************** WaitxTE movwf Count2 ; [1] waitxlp movlw D'30' ; [1] movwf Count ; [1] wait400lp nop ; [1] nop ; [1] decfsz Count,F ; [1] goto wait400lp ; [2] ; -------- ; 79 x 5 = 395us decfsz Count2,F ; [1] goto waitxlp ; [2] retlw 0 ; [2] ; total 2 (call) + W x (395 + 5) + 2 (return) ; w = 1 -> 406us @4MHz ; w = 2 -> 806us @4MHz ;************************************************************* ;initialize pic ;************************************************************* initialize ;clearing all ports CLRF nobit CLRF nobit2 clrf input clrf store clrf rotateright clrf Count clrf Count2 clrf ltime clrf rtime ;disable global interrupts during initialization bcf INTCON,7 ;calibrating the internal oscillator ; bsf STATUS,5 ;select bank 1 call 0x3FF movwf OSCCAL ; bcf STATUS,5 ;turn off the comparator bsf STATUS,5 clrf ANSEL ; clear ansel register bcf STATUS,5 clrf GPIO ; initialize General Purpose Input Output to 0 ;setting gpio register to the cosrresponding io pin bsf STATUS,5 bsf TRISIO,0 bsf TRISIO,1 bsf TRISIO,4 bcf TRISIO,2 bCf TRISIO,5 bcf STATUS,5 ;select bank 0 ;set bit 0:2 at register cmcon ;setting gp2 as digital output |offkan comparator bsf STATUS,5 bsf CMCON,0 bsf CMCON,1 bsf CMCON,2 BCF STATUS,5 ; VRCON register ; CVref circuit powered down,no Idd drain bsf STATUS,5 bcf VRCON, 7 bcf STATUS,5 ;**************************************************************** ;****timer1 module gate control********************************** ; disabling timer1 bsf STATUS, 5 ; select Bank 1 movlw b'01000100' ; disable TIMER1 movwf T1CON ; bcf STATUS, 5 ; select Bank 0 ;**************************************************************** ;weak pull-up register (wpu) ;each pull-up is automatically turned off when the pin is configured as an output bsf STATUS,5 movlw b'00010000' movwf WPU bcf STATUS,5 ;***************set pin for config_address regsiter ;OPTION Register ; OPTION_REG contains control bits to configure: ; Weak pull-ups on GPIO (see also WPU Register above) ; External GP2/INT interrupt ; TMR0 ; TMR0/WDT prescaler bsf STATUS,5 ; ---- Select Bank 1 ----- bcf OPTION_REG, NOT_GPPU ; GPIO pull-ups: enabled bsf OPTION_REG, INTEDG ; Interrupt Edge: on rising edge of GP2/INT pin bcf OPTION_REG, T0CS ; TMR0 Clock Source: internal instruction cycle (CLKOUT) bcf OPTION_REG, T0SE ; TMR0 Source Edge: increment low-to-high transition on GP2/T0CKI pin bcf OPTION_REG, 3 ; Prescaler Assignment: assigned to TIMER0 ; TMR0 Prescaler Rate: 1:2 bcf OPTION_REG, 2 ; Prescaler Rate Select bit 2 bcf OPTION_REG, 1 ; Prescaler Rate Select bit 1 bcf OPTION_REG, 0 ; Prescaler Rate Select bit 0 bcf STATUS, 5 ; ---- Select Bank 0 ----- ;*************************************************************** ;interrupt on-change register bsf STATUS,5 movlw b'00011011' ;enable global interrupts in order for the individual pin to be configured(kalo switch movwf IOC movlw b'00000000' ;peripheral interrupt register; disable movwf PIE1 bcf STATUS,5 movlw b'00001000' ;enable interrupt control register movwf INTCON ;****************************************************************** ;MAIN PROGRAM ;*****************************************************************8 MAIN bsf INTCON,7 ; enable global interrupts ; bsf rfena ; enable transmitter call BITCHECK ;***************************************************************** ;CHECK INPUT ;***************************************************************** BITCHECK btfsc nobit2,3 goto TRANSMIT movfw GPIO movwf input incf nobit2,f movfw nobit2 movwf nobit btfsc nobit2,2 goto checkleft ;for bit number 4,5,6,7 goto checkright ;for bit number 1,2,3,8 checkleft btfsc nobit2,1 goto rleft btfsc nobit2,0 goto bit5 goto rright1 return; checkright btfsc nobit2,3 goto rleft return; rright1 movlw d'5' movwf rtime return; rright decf rtime,f decfsz nobit goto rright ; movwf rtime rotater rrf input,f decfsz rtime goto rotater movfw input xorwf store,w movwf store goto BITCHECK return; bit5 movfw input xorwf store,w movwf store goto BITCHECK return; rleft movfw nobit movwf ltime decf ltime decf ltime decf ltime decf ltime decf ltime return rotatel rlf input,f decfsz ltime goto rotatel movfw input xorwf store,w movwf store goto BITCHECK return; TRANSMIT bsf GPIO,5 ; send preamble (50% duty cycle) Preamble ;send 16 bit movlw d'16' movwf BitCount ; init number of preamble bits PreL bsf txd ; ON movlw 1 call WaitxTE ; delay bcf txd ; OFF movlw 1 call WaitxTE ; delay decfsz BitCount,F ; loop goto PreL ; sync pause TXloop movlw d'10' call WaitxTE ; Theader = 10 x Te ; send 72 bit pattern movlw store ; lsb first movwf FSR TXNextByte movlw D'8' movwf BitCount TXNextBit rrf INDF,W ; 8 bit rotate | rotate right f through carry rrf INDF,F ; Carry contain lsb BC ONE ; branch on carry | goto ONE if bit is set ZERO ;wave pattern if the bit is zero movlw 2 ; movwf TimeHi ; +---+---+ +-- movlw 1 ; | | | movwf TimeLo ;---+ +---+ goto Trasm_BIT ; | 2Te Te | ONE ;wave pattern if the bit is one movlw 1 ; movwf TimeHi ; +---+ +-- movlw 2 ; | | | movwf TimeLo ;---+ +---+---+ ; | Te 2Te | Trasm_BIT bsf txd ; ON movf TimeHi,W call WaitxTE bcf txd ; OFF movf TimeLo,W call WaitxTE decfsz BitCount,F goto TXNextBit ; loop on bits ; guard time movlw TGUARD call WaitxTE org 0x3ff retlw 0x80 ;---------------------------------------------------------------------- end ; end of program directive ;----------------------------------------------------------------------
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