Timer 0 in DS_int_14 having a problem

Hi guys cant see what i am missing on this one , using DS_int_14 , to handle interupts call for timer 0 does not seem to activate

the code compiles , no errors

chip 16f1825

i have setup intcon reg for 1:256 PSA ,
its 8mhz clock
timer 0 is using the internal clock

the intent is timer 0 interupt every 25ms to go do subroutine _Timer0_Count

which just counts the interupts till it reaches 1520 ( aprox 38sec) then call a subroutine to go and do stuff

Note the other Int handler _getircode works

any suggestions


Cheers

Sheldon

Code:

---

' config for 16F1825           

#CONFIG
;----- CONFIG1 Options --------------------------------------------------
  __config _CONFIG1, _FOSC_INTOSC & _WDTE_OFF & _PWRTE_ON & _MCLRE_ON & _CP_OFF & _CPD_OFF & _BOREN_ON & _CLKOUTEN_OFF & _IESO_OFF & _FCMEN_ON

;----- CONFIG2 Options --------------------------------------------------
  __config _CONFIG2, _WRT_OFF & _PLLEN_OFF & _STVREN_ON & _BORV_HI & _LVP_OFF
#ENDCONFIG
 
 ' ---------- Set up DT_INTS-14 Routine for Instant Interupt handling  -----------

INCLUDE "DT_INTS-14.bas"
   
INCLUDE "ReEnterPBP.bas"
ASM
INT_LIST macro        ; IntSource  , Label        , Type, ResetFlag?

                INT_Handler IOC_INT  , _GetIRcode  ,  PBP, yes      ; call GetIRcode subroutine on Interupt
                INT_Handler TMR0_INT , _Timer0_Count,  PBP, yes      ; call Timer0_Count subroutine
        endm
        INT_CREATE                                                                ; Creates the Interrupt Processor
ENDASM
 
 
 '----------- 16F1825  - PIC chip settings --------------------                             
 
 OSCCON  = $70        ' Select 8Mhz , internal clock 
                        ' Bit 7 0 = 4xPLL disabled  1= 4xPLL enables ( overrided by conf word 2 setting -  PLLEN)
                        ' bits6-3 -  1111 = 16Mhz , 1110 = 8MHz or 32Mhz ( depends on 4xPLL - conf word 2)  1101 = 4 MHz, 1100 = 2MHz 1011 = 1MHz
                        ' bitS 0-1 - 00= Clock set by Conf word ,01 = Timer1 OSC , 1x = internal Osc Block
 
 APFCON0 = %00000000        'All Default - No change when using SPI  use SDO1 = RC2 , bit6=0
 APFCON1 = %00000000        'All Default  APFCON1 = %00000000
 
 
 
 CM1CON0 = $00                ' Disable / Clear comparator 1
 CM1CON1 = $00                ' Used with CM1CON0
 CM2CON0 = $00                ' Disable / Clear comparator 2
 CM2CON1 = $00                ' Used with CM2CON0
 CMOUT  = $00          ' Disable Comparitors output register - used only if comparitor on
 
 ANSELA =  %00000000    ' Set Port A - Digital I/O  , 0 = Digital  1 = Analog
 ANSELC =  %00000000    ' Set Port C - Digital I/O  , 0 = Digital  1 = Analog

 INLVLA = %00000000            ' Set Port A to TTL Levels 0 = TTL , 1 = SCHMITT TRIGGER - Used port reads and Interupt on Change
 INLVLC = %00000000            ' Set Port C to TTL Levels 0 = TTL , 1 = SCHMITT TRIGGER - Used port reads and Interupt on Change
 SRCON0 = %00000000    ' Disable Latched Outputs
 SRCON1 = %00000000    ' Used with SRCON0 register

 ADCON0 =  $00          ' Disable A/D
 ADCON1 =  $00          ' Disable A/D  - used with ADCON0 settings

 WPUA  = %00001100            '  Port A - Turn off week Pullups 1=ON , for each port ( globle enable set in option_reg.7)set wpu on PortA.3 as input only - ref spec
 WPUC  = %00000000    '  Port C - Turn off week Pullups 1=ON  For each port

 DACCON0 = $00          ' Disable D/A
 DACCON1 = $00          ' Disable D/A - used with DACCON0
 FVRCON  = $00          ' Disable Fixed Voltage Ref

 INTCON = 0            ' Interupts Clear at start- GIE,PEIE,TMR0IE,INTE,IOCIE = on,TMR0IF,INTF,IOCIF
 IOCAN.4 = 1            ' Enable interupt on change on portA.4 for negative going edge  ( for getIR routine )
 IOCAF.4 = 0            ' Clear Interupt on Change flag on portA.4
 
 OPTION_REG.7 = 1      ' Weak Pullups disabled  1 = globel disable 0 = globel enable ( set by each port - WPUA & WPUC settings)
 OPTION_REG.6 = 0      ' Interupt on Falling Edge of INT pin  0= falling edge  1= rising edge
 OPTION_REG.5 = 0      ' TMR0 clock source - 1=T0clk pin 0=internal clock
 OPTION_REG.4 = 0      ' TMR0 0=L/H of TOCKI pin  1=H/L of TOCKI pin
 OPTION_REG.3 = 0      ' Use Prescaller for TMR0  0= Yes , 1 = No
 OPTION_REG.2 = 1      ' Timer0 prescaler Rate Select bits 2-0(set to 1:256)
 OPTION_REG.1 = 1      ' 000 = 1:2  , 001= 1:4  , 010 = 1:8  , 011 = 1:16
 OPTION_REG.0 = 1      ' 100 = 1:32 , 101 = 1:64, 110 = 1:128 , 111 = 1:256
 
 T1CON  = %01110100    ' Timer 1 ,bit7-6 = TMR1 CLK source 00 = Instuction Clk(Fosc/4),01 =sys clk,10=ext clk,11=cap sense osc
                        ' bit5-4 = TMR1 prescale 11= 1:8 ,bit3=0 LP off,bit2=1 no sync ext CLK ,bit1= 0 n/a,Bit0=0 Timer 1 on/off
 T1GCON = %00000000    ' Timer 1 Gate Control bit7 0= counts regardless of gate 1 = gates in use  , bit6 gate active when 1= High  ,0=low 
                        ' bit5 0= toggle mode diabled 1= enabled  bit4 single pulse mode 1- en 0= dis, bit 2 -status bit,1-0 - gate source sel
                         
 T2CON  = %01110011    ' Timer 2 off + 1:15 postscale ,1:64 prescale ( bit 7 = x, bit6-3 1110 = 1:15 postscale, bit2=0 timer off ,bit1-0 = prescale 10 = 16 , 11= prescale 64 
 T4CON  = %00000000            ' POSTSCALER 1/1,STOP,PRESCALER 1/1
 T6CON  = %00000000        ' POSTSCALER 1/1,STOP,PRESCALER 1/1

 TMR0 = 0              ' Clear TMR0 MODULE REGISTER
 
 TMR1H = 0              'CLEAR TMR1H MODULE REGISTER
 TMR1L = 0              'CLEAR TMR1L MODULE REGISTER
 
 TMR2 = 0                            'CLEAR TMR2 MODULE REGISTER
 TMR4 = 0                            'CLEAR TMR4 MODULE REGISTER
 TMR6 = 0                            'CLEAR TMR6 MODULE REGISTER
 
 'PR2 = 255              ' Timer 2 Preload value
 'PR4 = 255              ' Timer 4 Preload value
 'PR6 = 255              ' Timer 6 Preload value

 

DEFINE OSC 8            ' Timing referance for pause , pauseus commands
DEFINE PULSIN_MAX 21600  ' Maximum counts( clock ticks) allowed before pulsin times out( 21600 ^ 5ms =  108 ms)
                        ' Norm IR pulse length is 108ms 

' --------- PIC Timers & sync variables ------------
  T0Count  VAR WORD      ' varable in Timer 0 counter interupt handler

@ INT_ENABLE IOC_INT          ; Enable PortA Change on Interupt
@ INT_ENABLE TMR0_INT    ; enable Timer 0 interupts





' ============ Timer 0 Interupt handler ================

 Timer0_Count:

 T0Count = T0Count + 1                        ' inc counter on intrupt flag
 TMR0 = 60                                        ' preload  256-196 = 60 to gen a 25ms timer using 1:256 prescale 
 if T0Count = 1520 then  Smooth_reset
@ INT_RETURN

---

Hi,

I just wonder if your TMR 0 interrupt flag is correctly reset ... ;)

Alain

tried adding INTCON.2 = 0
in the called sub but it did not seem to make any dif , it seems the subroutine is never called ???

mmm, the general routine seems to work on the 12F683 via a simulator , but not on the 16F1825 , i dont have a simulator for the 16f1825 atm

Try not leaving the interrupt before it is finished.

found problem :

" INTCON = 0 ' Interupts Clear at start- GIE,PEIE,TMR0IE,INTE,IOCIE = on,TMR0IF,INTF,IOCIF

Was set after setting up the ASM calls for DT_int_14 started , which cleared its good work , not clear why it did not effect other routine that uses IOCIF , perhaps cos i clear and set the individual int flags for IOC on this chip ???

also , the DT_int_14 does not clear the timer0 int flag and needs to be done in the service routine , adding stop and start timer 0 to the routine was required and should have been there to start with , dont think DT_int_14 would/ should do that as its just monitors the int flag


so the commands for the int call routine are

1. INTCON.5 = 0 ' stop timer 0

2. go do what u want to do
4. TMR0 = 60 ' reload timer 0 start point constant
5. INTCON.5 = 1 ' start timer 0
6. @ INT_RETURN

one item i am noticing is that if the INT routine call has a another sub routine that is activated within it it does not seem to return back to the org int call , i am i missing something ?

That's what Dave was trying to say. You have the following line in your ISR

Code:

---

if T0Count = 1520 then  Smooth_reset

---

This is effectively a GOTO so the execution jumps to the Smooth_reset routine and doesn't return to the ISR from there.

/Henrik.

thanks Hendrick , i did not follow what he ment by the comment

I eventually found that code

Code:

---

if (T0Count = Smoothfade) and Fade_flag = 2 then Smooth_reset

---

was not returning , thought it was acted upon the same as

Code:

---

if (T0Count = Smoothfade) and Fade_flag = 2 then gosub Smooth_reset

---

but it is not , as you say , the first is a goto and 2nd statement with the " gosub" returns and works fine


Well something i did not know, i know now


More fun learning ahead

Cheers

sheldon

Yeah, a subroutine must always end with a RETURN and must always be jumped to with a GOSUB.
If you GOTO a subroutine it will fail badly once it hits the RETURN statement because it will then "return" to the wrong place because the correct place hasn't been stored.

* Never GOSUB anything not ending with RETURN.
* Never GOTO anything which does end with RETURN.

The manual is pretty clear on that specifying a label in an IF statement causes a GOTO when the expression is evaluated true.

I'm glad you're moving forward!
/Henrik.

cheers Hendrick