tmr2 interrupt problem

[ADCON]

Dear,

I still have a problem.

I have merged all the code and the beginning works fine now.
It go's to the loop: makes a I2C read.
Go's to another loop for I2C write(only if needed).

Then it have to wait for the the interupt.
At the interrupt is starts to shiftout the data for the display.
Until here it works fine.

The problem is: it keeps doing that and NEVER goes back to the loop..

This didn't I know becose in the testprogram there was noting to do in the loop..

I can post the code when someone needs it but it's the same as above, only with some onther code inside it.

Dos anyone know what I do wrong?

[mister_e]

ISRs should be keep as short as possible, i feel that what you do inside may need much time than 2mSec?

If so... you may stop the timer, do your stuff, re-start the timer and clear the interrupt flag.. but yeah you loose all of this needed 2mSec accuracy... even using Darrel's favorite ON INTERRUPT

Try to reduce your 2mSec to let's say 5-10 mSec
But that's a feeling. Post your whole code here with the I2C stuff.

[ADCON]

My isr is long, but at 4MHz and no delay instructions it has not to be the problem.
Well, I tried to set the presale to 1:16. 1:4 had to make a interrupt every 2mSec.
after that I tried to turn off the timer and after that, turn it back on. All had no effect.
So, I came back here.

This is all my code:
first config, var's and isr
then main loop
after that the complete menu
Much of the code was for a rtc-clock using a lcd. Thats why some of the loops are empty now.

 @ device pic16F628a, INTRC_OSC_NOCLKOUT
 @ device pic16F628a, MCLR_ON
 @ device pic16F628a, LVP_OFF
 @ device pic16F628a, WDT_OFF
 @ device pic16F628a, PWRT_ON
 @ device pic16F628a, BOD_OFF'ON   
INCLUDE "modedefs.bas"  'for shiftout
pause 50

' Defines 
' ---------------- 
'I2C pins
DS_SCL VAR PORTA.0 	' I2C clock pin 
DS_SDA VAR PORTA.1 	' I2C data pin 
'RTC CON %11010000 	' RTC device address (byte addressing) not needed

'Setting the RTC so we can get out 1Hz tick output 
'------------------------------------------------- 
' -------------- RTC definitions ----------------- 
SecReg 	CON $00 	' seconds address (00 - 59)
' MSB of SecReg must be set to a 0 to enable RTC 
MinReg CON $01 	    ' minutes address (00 - 59) 
HourReg CON $02 	' hours address (01 - 12) or (00 - 23) 
DayReg CON $03 	    ' day address (1 - 7) 
DateReg CON $04 	' date address (01 - 28/29, 30, 31) 
MonthReg CON $05 	' month address (01 - 12) 
YearReg CON $06 	' year address (00 - 99) 
ContReg CON $07 	' control register 
RTCflag CON 0 		' RTC flag (location 0 of internal EEPROM) 
cntrl CON %00010000 ' sets the SQW/OUT to 1Hz pulse, logic level low 

' The variable below holds the values entered: 
'menu var's
_sec 	VAR BYTE ' $00 set seconds 
_min 	VAR BYTE ' $56 set minutes 
_hr 	VAR BYTE ' $23 set hour 
_day 	VAR BYTE ' $06 set day 
_date 	VAR BYTE ' $28 set date 
_mon 	VAR BYTE ' $02 set month 
_yr 	VAR BYTE ' $03 set year 

'rtc var's
sec 	VAR BYTE ' seconds 
MINs 	VAR BYTE ' minutes 
hr 	    VAR BYTE ' hours 
day 	VAR BYTE ' day 
date 	VAR BYTE ' date 
mon 	VAR BYTE ' month 
yr 	    VAR BYTE ' year 

'button input     
'-------------------
	SetButton var PORTa.7	' Press to Set/memorise Button
    DecButton var PORTa.3	' Press to Decrement Button
	IncButton var PORTa.2	' Press to Increment Button

'other var's
'------------------
	CounterA var byte       ' General purpose Variable
	CounterB var byte       ' General purpose Variable
	CounterC var byte       ' General purpose Variable
    CounterD var byte       ' General purpose Variable
    ButtonRepeat con 200	' Timeperiod (in mS for Edit Buttons auto-repeat
    			         	' should you want to hold them down...
    RTCCtrl var byte        ' Control
    TimeOut var word        ' Variable for SetUp Menu Time-Out
    SetTime var byte	    ' 12/24 Hour Clock
    RTCWDay var byte	    ' Weekday 
    timeformat var word     ' place for displaying am/pm
    counter var byte
    counter2 var byte
    counter3 var word       ' delaycounter
    counter4 var word       ' counter at redisplayloop
    segments var byte
    myBCD var byte
    toDEC var byte 
    
'I/O pins
'port conditions
'---------------        
        CMCON=7
        TRISA=0
        TRISB=0
        PORTA=0
        PORTB=0

'timer and interruptconditions
'----------------      
        PIE1 =  %00000010
                '0------- Disable EE write complete interrupt
                '-0------ Disable comparator interrupt
                '--0----- Disable USART receive interrupt
                '---0---- Disable USART transmit interrupt
                '----x--- unimplemented
                '-----0-- Disable CCP1 interrupt
                '------1- Enable TMR2 to PR2 match interrupt
                '-------0 Disable TMR1 overflow interrupt
                
        T2CON = %00000010
                'X------- Unimplemented
                '-0000--- postscale 1:1
                '-----0-- Timer2 off
                '------10 prescaler 1:16
                                   
        GIE     VAR INTCON.7
        PEIE    VAR INTCON.6
        TMR2IF  VAR PIR1.1
        TMR2ON  VAR T2CON.2
        RELOAD CON 131
        
        ON INTERRUPT GOTO ISR
        TMR2 = RELOAD
        PR2 = 0   ' load period register for 2mSec 
        PEIE = 1    ' Enable peripheral interupt
        GIE = 1     ' enable Global interrupt
        TMR2ON = 1  ' TMR2 ON
        GOTO LOOP                

        disable
        ISR:             'interruptroutine
        TMR2ON=0
'later to use to reduce the isr text. then only shiftout the var's
if counter3=>200 then 'number of shiftouts
counter3=0
else 
counter3=counter3+1
endif

'hours
'the one that is 0 wil blink
'for segments the opposite
counter = %01111111     '1 segment
toDEC = hr
if hr.6=1 then          '12 uurs mode
    todec = todec <<3
    todec = todec >>7
else                    '24 uurs mode
    todec = todec <<2
    todec = todec >>6
endif
gosub findsegments
if hr.6 = 1 then        'add in the am/pm indication
    if hr.5 = 1 then
        segments.7 = %1
    endif
endif
gosub segmentsshiftout

counter = %10111111 '2 segment
toDEC = hr
toDEC = toDEC << 4 'shiftout unusable data
todec = todec >> 4 'shiftback usable data
gosub findsegments
if portA.6 = 1 then segments.7 = %1    'add the blinkin dot
gosub segmentsshiftout

'minits
counter = %11011111  '3 segment
toDEC = MINs
todec = todec >> 4 'shiftback usable
gosub findsegments
gosub segmentsshiftout

counter = %11101111    '4 segment
toDEC = MINs
todec = todec << 4 'shiftout unusable data
todec = todec >> 4  
gosub findsegments
gosub segmentsshiftout

'seconds
counter = %11110111    '5 segment
toDEC = sec
todec = todec >> 4 'shiftback usable
gosub findsegments
gosub segmentsshiftout

counter = %11111011 '6 segment
toDEC = sec
todec = todec << 4 'shiftout unusable data
todec = todec >> 4 
gosub findsegments

if hr.6=1 then      'mode indication
segments.7=%1
endif
gosub segmentsshiftout

counter = %11111111 'to take care that no segment is blinking harder
todec = %00000000'todec >> 4 
gosub segmentsshiftout

segmentsshiftout:
SHIFTOUT PORTB.0, PORTB.1, LSBFIRST,[counter\8,segments\8]   'data, clock
pulsout PORTA.4,1        
return        
findsegments:
if todec=%00000000 then '0
    segments = %01111110
    endif
if todec=%00000001 then  '1
    segments = %00110000
    endif
if todec=%00000010 then  '2
    segments = %01101101
    endif
if todec=%00000011 then  '3
    segments = %01111001
    endif
if todec=%00000100 then   '4
    segments = %00110011
    endif
if todec=%00000101 then   '5
    segments = %01011011
    endif
if todec=%00000110 then   '6
    segments = %01011111
    endif
if todec=%00000111 then   '7
    segments = %01110000
    endif
if todec=%00001000 then   '8
    segments = %01111111
    endif
if todec=%00001001 then   '9
    segments = %01111011
    endif
return
        TMR2 = RELOAD
        TMR2ON = 1        
        TMR2if=0  ' Clear interrupt flag

        resume
        enable
        
        
LOOP:
I2CRead DS_SDA,DS_SCL,$D0,$00, [sec,MINs,hr,day,date,mon,yr] ' Read Ds1307 
	If sec.7=1 then goto coldstart	
    If setbutton = 0 then       'if setbutton is pressed
        _hr=hr
        _min=MINs
        _sec=sec
     gosub SetButtonRelease    
     Gosub SetTimeAndDate 'after release    
   endif
counter3=0
repeat     'show the segments for 5 times.
pauseus 10    
until counter3 > 5
GoTo Loop 
end

Segmentswrite2:'write settimevar's to timevar's in bcd
			CounterA=_hr
			If SetTime=1 then
				If CounterA>12 then CounterA=CounterA-12
				If CounterA=0 then CounterA=12
				endif
			Gosub ConvertBCD
			hr=CounterB
					' Save the Hours Value
			If SetTime=1 then
				hr.6=1
					' Save the 12 Hour Mode Flag
				If _hr=>12 then hr.5=1
					' Save the 'PM' Flag
				endif
				'
				'	Save Minutes
				'	------------
			CounterA=_min
			Gosub ConvertBCD
			MINs=CounterB
				'
				'	Save Seconds
				'	------------
			CounterA=_sec
			Gosub ConvertBCD
			sec=CounterB
			'gosub segmentswrite
return

'paste here the other half of the code

[ADCON]

the text wat to long to set in one message

'paste here the above code

SetTimeAndDate: 
'============= 
Setup:
    SetTime=hr.6	' Determines 12/24 Hour mode
	If SetTime=1 then
				' Regardless of 12/24 options, SetHour always
				' contains the hours in 24 hour clock format
				' otherwise there's twice the amount of work
				' to keep track in the edit routines
		_hr=(hr>>4)&$01
				' if 12-hour mode
		else
		_hr=(hr>>4)&$03
				' if 24 hour mode
		endif
	_hr=_hr*10+(hr&$0F)
	If SetTime=1 then
		If hr.5=1 then
			If _hr<12 then _hr=hr+12
				' Add-in the AM/PM indicator
			else
			If _hr=12 then _hr=0
			endif
		endif
	_Min=((Mins>>4)&$0F)*10+(Mins&$0F)
	_Sec=((Sec>>4)&$0F)*10+(sec&$0F)
	_yr=((yr>>4)&$0F)*10+(yr&$0F)
	_mon=((mon>>4)&$0F)*10+(mon&$0F)
	_day=((day>>4)&$0F)*10+(day&$0F)
		'
		'	Setup Menu Loop
		'	---------------
	CounterC=0		' Set to Start of Setup (seven steps from 0 to 6)
	TimeOut=0		' Zero the Time-Out counter
SetupLoop:
		'
		'	Now Display the Data
		'	--------------------
SetupDisplayLoop:
			'
			' 	12/24 Hour Option
			'	-----------------
	    '
		'	The Data-Entry Bit
		'	------------------
SetupEntryLoop:         'datainput.
			'
			'	Decrement(down) Button Pressed
			'	------------------------
	If DecButton=0 then
				'
				'	12/24 Clock Selection
				'	---------------------
		If CounterC=0 then
			If SetTime=0 then 
				SetTime=1
				else
				SetTime=0
				endif
			endif
				'
				'	Decrement Hours
				'	---------------
		If CounterC=1 then
            If _hr=0 then
				_hr=23
				else
				_hr=_hr-1
				endif
			endif
				'
				'	Decrement Minutes
				'	-----------------
		If CounterC=2 then
			If _Min=0 then
				_Min=59
				else
				_Min=_Min-1
				endif
			endif
				'
				'	Decrement Seconds
				'	-----------------
				'	Kinda overkill to include setting seconds,
				'	but if you got codespace to burn...
		If CounterC=3 then
			If _Sec=0 then
				_Sec=59
				else
				_Sec=_Sec-1
				endif
			endif
		gosub Pauseloop
        TimeOut=0
        Goto SetUpDisplayLoop
		endif
			'
			'	Increment(up) Button Pressed
			'	------------------------
			' 	This is just like Decrement but opposite...
	If IncButton=0 then
				'
				'	12/24 Clock Selection
				'	---------------------
		If CounterC=0 then
			If SetTime=1 then 
				SetTime=0
				else
				SetTime=1
				endif
			endif
				'
				'	Increment Hours
				'	---------------
		If CounterC=1 then
            If _hr=>23 then
				_hr=0
				else
				_hr=_hr+1
				endif
			endif
				'
				'	Increment Minutes
				'	-----------------
		If CounterC=2 then
			If _min=>59 then
				_Min=0
				else
				_Min=_Min+1
				endif
			endif
				'
				'	Increment Seconds
				'	-----------------
				'	Kinda overkill to include setting seconds,
				'	but if you got codespace to burn...
		If CounterC=3 then
			If _Sec=>59 then
				_Sec=0
				else
				_Sec=_Sec+1
				endif
			endif
			
		gosub Pauseloop
        TimeOut=0
		Goto SetupDisplayLoop
		endif
			'
			'	Set Button Pressed
			'	------------------
	If setbutton =0 then
       CounterC=CounterC+1		' Increment Menu Item
		TimeOut=0
	endif
		If CounterC>3 then        'old menu counterC>6#########################
				' Save Data if all edit items exhaused
				'
				'	Save 12/24 Hours to BCD DS1307's Format
				'	---------------------------------------
			CounterA=_hr
			If SetTime=1 then
				If CounterA>12 then CounterA=CounterA-12
				If CounterA=0 then CounterA=12
				endif
			Gosub ConvertBCD
			hr=CounterB
					' Save the Hours Value
			If SetTime=1 then
				hr.6=1
					' Save the 12 Hour Mode Flag
				If _hr=>12 then hr.5=1
					' Save the 'PM' Flag
				endif
				'
				'	Save Minutes
				'	------------
			CounterA=_min
			Gosub ConvertBCD
			MINs=CounterB
				'
				'	Save Seconds
				'	------------
			CounterA=_sec
			Gosub ConvertBCD
			sec=CounterB
			
				'
				'	Do the Business
				'	---------------
rtcwrite:
			I2CWrite DS_SDA, DS_SCL,$D0,$00,[sec,MINs,hr,RTCWDay,day,mon,yr,RTCCtrl]
			Gosub SetButtonRelease
			Goto ReDisplay
			endif
		Gosub SetButtonRelease
		Goto SetupLoop	' Loop for Next Menu Item
		'
		'	Menu TimeOut Counter
		'	--------------------
	gosub Segmentswrite2
	TimeOut=TimeOut+1        'not jet working good
    If TimeOut>20000 then goto ReDisplay
				' User paused too long
				' Return User to Time & Date Display
				' This will however bounce the User to the original
				' Setup Menu start point if the DS1307 has not 
				' been initialised
	Goto SetupEntryLoop	' Loop for Button Press

Pauseloop: 'some timedelay
counter3=0
repeat
    pauseus 10
until counter3 > 50
return

'just a routine to make sure you didn't push the button by faulth
'------------------------------------
SetButtonRelease: 'delay for button
	counter3=0
    while setbutton=0
        pauseus 10
    Wend
	if counter3=>29 then
        repeat
            pauseus 10
        until counter3 > 70
    else 
        goto loop    
    endif
    Return

FindDays:    'deleted
	Return	
DisplayMonth:'deleted

DisplaySequence: 'deleted
	Return

	'
	'	Subroutine Converts back to BCD
	'	-------------------------------
		' CounterA is the entry variable
		' CounterB holds the converted BCD result on exit
ConvertBCD:
	CounterB=CounterA DIG 1
	CounterB=CounterB<<4
	CounterB=CounterB+CounterA DIG 0
	Return
	
Redisplay:   'deleted
return

Am_or_Pm:     'deleted
return  

coldstart:   'only started when rtc starts from cold
'--xx--
_yr=0:_date =0:_mon =0:_day=0:_hr=0:_min=0:_sec=0 

' The constants below set the RTC to: 16:30:00 on 13-07-2003 
_yr=$03 
_mon=$07 
_date=$13 
_hr=$16 
_sec=$00 
_min=$30 
I2CWrite DS_SDA, DS_SCL, $D0,$00,[_sec,_min,_hr,_day,_date,_mon,_yr,cntrl] 
Return

[mister_e]

i see you use some GOSUBs & Return in your ISR... not a good idea to me...

Observe the way your program will flow, assuming there's no problem with the use of Gosub and Return (erm), your program will execute all lines.. and finally jump to...

        counter = %11111111 'to take care that no segment is blinking harder
        todec = %00000000'todec >> 4 
        gosub segmentsshiftout
        
segmentsshiftout:
        SHIFTOUT PORTB.0, PORTB.1, LSBFIRST,[counter\8,segments\8]   'data, clock
        pulsout PORTA.4,1        
        return        

it's kinda dangerous here... once it have execute once the segmentsshiftout sub, it will execute it once again and meet a RETURN without a GOSUB... where the program branch now??? i guess at the begining of your ISR... or.. mmm... resume to your main loop, but as you NEVER EVER clear the interrupt flag, it will automatically jump back to your ISR.

try to add a GOTO after your last GOSUB segmentsshiftout, which will send it at the end of your ISR...

        counter = %11111111 'to take care that no segment is blinking harder
        todec = %00000000'todec >> 4 
        gosub segmentsshiftout

	GOTO RESUME_ISR	' <-- Add this
	
segmentsshiftout:
        SHIFTOUT PORTB.0, PORTB.1, LSBFIRST,[counter\8,segments\8]   'data, clock
        pulsout PORTA.4,1        
        return        
	'
	'
	'
	'
	'
RESUME_ISR: ' <-- And this
        TMR2 = RELOAD
        TMR2ON = 1        
        TMR2if=0  ' Clear interrupt flag

        resume
        enable

[ADCON]

thanks,

here s my progress for now:
First I added the lines you gave me. unfortunatly it didn't work.
I put somethings at a more logical place(tmr2if=0 at the top of isr)
Then I replaced all the gosubs by the real text. it cost me for aboud 500 words more but luckily there was enough space at the 628 (i haven't a 648 at stock).
Then I began thinking aboud the stackadresses. But that was not the option because there was not a gosub at the loop so the only things at the stack had to be the adress for the return after the interrupt and max 1 gosub adress from inside the ISR.

When I looked at the helpfile I got an idea. It is also possible to place a label after the resume command. I added loop after the resume command and it works for now.

>>The only problem now is that after the 'resume loop' command I have just 2msec to change my settings:P That is not possible but maby you get now an adea for what I'm doing wrong.

So, I tried that at the prevous version of the program. This works the same, so with the gosubs inside the ISR.

Here is my code for now: under the loop didn't I change anything so that is not posted.

 @ device pic16F628a, INTRC_OSC_NOCLKOUT
 @ device pic16F628a, MCLR_ON
 @ device pic16F628a, LVP_OFF
 @ device pic16F628a, WDT_OFF
 @ device pic16F628a, PWRT_ON
 @ device pic16F628a, BOD_OFF'ON   
INCLUDE "modedefs.bas"  'for shiftout
pause 50

' Defines 
' ---------------- 
'I2C pins
DS_SCL VAR PORTA.0 	' I2C clock pin 
DS_SDA VAR PORTA.1 	' I2C data pin 
'RTC CON %11010000 	' RTC device address (byte addressing) not needed

'Setting the RTC so we can get out 1Hz tick output 
'------------------------------------------------- 
' -------------- RTC definitions ----------------- 
SecReg 	CON $00 	' seconds address (00 - 59)
' MSB of SecReg must be set to a 0 to enable RTC 
MinReg CON $01 	    ' minutes address (00 - 59) 
HourReg CON $02 	' hours address (01 - 12) or (00 - 23) 
DayReg CON $03 	    ' day address (1 - 7) 
DateReg CON $04 	' date address (01 - 28/29, 30, 31) 
MonthReg CON $05 	' month address (01 - 12) 
YearReg CON $06 	' year address (00 - 99) 
ContReg CON $07 	' control register 
RTCflag CON 0 		' RTC flag (location 0 of internal EEPROM) 
cntrl CON %00010000 ' sets the SQW/OUT to 1Hz pulse, logic level low 

' The variable below holds the values entered: 
'menu var's
_sec 	VAR BYTE ' $00 set seconds 
_min 	VAR BYTE ' $56 set minutes 
_hr 	VAR BYTE ' $23 set hour 
_day 	VAR BYTE ' $06 set day 
_date 	VAR BYTE ' $28 set date 
_mon 	VAR BYTE ' $02 set month 
_yr 	VAR BYTE ' $03 set year 

'rtc var's
sec 	VAR BYTE ' seconds 
MINs 	VAR BYTE ' minutes 
hr 	    VAR BYTE ' hours 
day 	VAR BYTE ' day 
date 	VAR BYTE ' date 
mon 	VAR BYTE ' month 
yr 	    VAR BYTE ' year 

'button input     
'-------------------
	SetButton var PORTa.7	' Press to Set/memorise Button
    DecButton var PORTa.3	' Press to Decrement Button
	IncButton var PORTa.2	' Press to Increment Button

'other var's
'------------------
	CounterA var byte       ' General purpose Variable
	CounterB var byte       ' General purpose Variable
	CounterC var byte       ' General purpose Variable
    CounterD var byte       ' General purpose Variable
    ButtonRepeat con 200	' Timeperiod (in mS for Edit Buttons auto-repeat
    			         	' should you want to hold them down...
    RTCCtrl var byte        ' Control
    TimeOut var word        ' Variable for SetUp Menu Time-Out
    SetTime var byte	    ' 12/24 Hour Clock
    RTCWDay var byte	    ' Weekday 
    timeformat var word     ' place for displaying am/pm
    counter var byte
    counter2 var byte
    counter3 var word       ' delaycounter
    counter4 var word       ' counter at redisplayloop
    segments var byte
    myBCD var byte
    toDEC var byte 
    
'I/O pins
'port conditions
'---------------        
        CMCON=7
        TRISA=0
        TRISB=0
        PORTA=0
        PORTB=0

'timer and interruptconditions
'----------------      
        PIE1 =  %00000010
                '0------- Disable EE write complete interrupt
                '-0------ Disable comparator interrupt
                '--0----- Disable USART receive interrupt
                '---0---- Disable USART transmit interrupt
                '----x--- unimplemented
                '-----0-- Disable CCP1 interrupt
                '------1- Enable TMR2 to PR2 match interrupt
                '-------0 Disable TMR1 overflow interrupt
                
        T2CON = %00000010
                'X------- Unimplemented
                '-0000--- postscale 1:1
                '-----0-- Timer2 off
                '------10 prescaler 1:16
                                   
        GIE     VAR INTCON.7
        PEIE    VAR INTCON.6
        TMR2IF  VAR PIR1.1
        TMR2ON  VAR T2CON.2
        RELOAD CON 131
        
        ON INTERRUPT GOTO ISR
        TMR2 = RELOAD
        PR2 = 0   ' load period register for 2mSec 
        PEIE = 1    ' Enable peripheral interupt
        GIE = 1     ' enable Global interrupt
        TMR2ON = 1  ' TMR2 ON
        GOTO LOOP                

        disable
        ISR:             'interruptroutine
        TMR2if=0  ' Clear interrupt flag        
        TMR2ON=0
'counter3 to reduce later the isr text. then only shiftout the var's
if counter3=>200 then 'number of shiftouts
counter3=0
else 
counter3=counter3+1
endif

'hours
'the one that is 0 wil blink
'for segments the opposite
counter = %01111111     '1 segment
toDEC = hr
if hr.6=1 then          '12 uurs mode
    todec = todec <<3
    todec = todec >>7
else                    '24 uurs mode
    todec = todec <<2
    todec = todec >>6
endif
gosub findsegments
if hr.6 = 1 then        'add in the am/pm indication
    if hr.5 = 1 then
        segments.7 = %1
    endif
endif
gosub segmentsshiftout

counter = %10111111 '2 segment
toDEC = hr
toDEC = toDEC << 4 'shiftout unusable data
todec = todec >> 4 'shiftback usable data
gosub findsegments
if portA.6 = 1 then segments.7 = %1    'add the blinkin dot
gosub segmentsshiftout

'minits
counter = %11011111  '3 segment
toDEC = MINs
todec = todec >> 4 'shiftback usable
gosub findsegments
gosub segmentsshiftout

counter = %11101111    '4 segment
toDEC = MINs
todec = todec << 4 'shiftout unusable data
todec = todec >> 4  
gosub findsegments
gosub segmentsshiftout

'seconds
counter = %11110111    '5 segment
toDEC = sec
todec = todec >> 4 'shiftback usable
gosub findsegments
gosub segmentsshiftout

counter = %11111011 '6 segment
toDEC = sec
todec = todec << 4 'shiftout unusable data
todec = todec >> 4 
gosub findsegments

if hr.6=1 then      'mode indication
segments.7=%1
endif
gosub segmentsshiftout

counter = %11111111 'to take care that no segment is blinking harder
todec = %00000000'todec >> 4 
gosub segmentsshiftout
GOTO RESUME_ISR	' <-- Add this

segmentsshiftout:
SHIFTOUT PORTB.0, PORTB.1, LSBFIRST,[counter\8,segments\8]   'data, clock
pulsout PORTA.4,1        
return        

findsegments:
if todec=%00000000 then '0
    segments = %01111110
    endif
if todec=%00000001 then  '1
    segments = %00110000
    endif
if todec=%00000010 then  '2
    segments = %01101101
    endif
if todec=%00000011 then  '3
    segments = %01111001
    endif
if todec=%00000100 then   '4
    segments = %00110011
    endif
if todec=%00000101 then   '5
    segments = %01011011
    endif
if todec=%00000110 then   '6
    segments = %01011111
    endif
if todec=%00000111 then   '7
    segments = %01110000
    endif
if todec=%00001000 then   '8
    segments = %01111111
    endif
if todec=%00001001 then   '9
    segments = %01111011
    endif
return
        RESUME_ISR: ' <-- And this
        TMR2ON=1
        TMR2 = RELOAD
        resume loop
        enable
    
LOOP:
I2CRead DS_SDA,DS_SCL,$D0,$00, [sec,MINs,hr,day,date,mon,yr] ' Read Ds1307 
	If sec.7=1 then goto coldstart	
    If setbutton = 0 then       'if setbutton is pressed
        _hr=hr
        _min=MINs
        _sec=sec
     gosub SetButtonRelease    
     Gosub SetTimeAndDate 'after release    
   endif
counter3=0
repeat     'show the segments for 5 times.
pauseus 10    
until counter3 > 5
GoTo Loop 
end

[mister_e]

Well, believe it or not, and if MPLAB StopWatch don't lie, your ISR need 4.6 mSec to execute... and usually you want to reload the timer before re-starting it.

Do you have any schematic of your thing and a brief description of what you want to do?