Timer0 in PIC16F72

[koolguy]

Hi,

The problem was i think it has internal RC oscillator i will connect crystal and tell what happen..

 

[Ian Rogers]

Yes!! It can be confusing.. However the newer chips actually have oscillator modules that allow speeds of up to 8Mhz.

 

[jpanhalt]

Can you point to the section describing the internal oscillator? I could not find it. Moreover, if there is an internal RC oscillator, you would need to include some statements to assign the frequency. You did not include those.

Why not follow the datasheet? It is the best option you have. Have you confirmed that you have a working oscillator? If not, why not?

Edit: There is simply no mention of an internal oscillator of any type. Please review this:

John

 

[ericgibbs]

hi ritesh,
What are the R/C values of your RC Oscillator circuit.?

 

[koolguy]

hi ritesh,
What are the R/C values of your RC Oscillator circuit.?

I have misread the data sheet it want external rc so, problem is nothing

 

[Pommie]

OK, I was stupid enough to read the first 1.5 pages. I have been punished. I will not read the next 20. (wait)

Please forgive me.

Mike.

 

[Ian Rogers]

For those of you who are pondering... Ritesh assumed that the chip has an internal RC block, it however, does not so I think he'll apply an extenal crystal..

 

[ericgibbs]

hi ritesh,
Download this free PIC delay calculator, it should give you guidance on how write an assembler delay loop.
http://www.biltronix.com/picloops.html

Copy and Paste the delay code into your program.
E

 

[Ian Rogers]

I like this one.... It creates C code as well.... It may not help with ASM but I'll include it here
http://eng-serve.com/pic/pic_timer.html

 

[jpanhalt]

Since Ritesh seems to be interested in Assembly, I suggest PicList as a great resource:


There are a few delay code generators there, but this is the one I use when I don't use Mike McLaren's (K8LH):


Finally, assuming Ritesh settles on 4 to 20 MHz, he might be able to use this code directly (0.5 second at 4 MHz)(from PicList):

; Delay = 0.5 seconds
; Clock frequency = 4 MHz

; Actual delay = 0.5 seconds = 500000 cycles
; Error = 0 %

cblock
d1
d2
d3
endc
Delay     ;499994 cycles
     movlw 0x03
     movwf d1
     movlw 0x18
     movwf d2
     movlw 0x02
     movwf d3
Delay_0
     decfsz d1, f
     goto $+2
     decfsz d2, f
     goto $+2
     decfsz d3, f
     goto Delay_0

;6 cycles
     goto $+1
     goto $+1
     Return

I usually leave out the fine tuning (i.e., the two goto $+1's at the end).
John

 

[large_ghostman]

Ritesh if you have given up on C and now going with ASM then take a look at nigels page he has loads of tutorials for ASM, but can i ask why the move from C??

 

[koolguy]

why the move from C??

to understand pic arch more deeply for its use..

 

[ericgibbs]

Ritesh if you have given up on C and now going with ASM then take a look at nigels page he has loads of tutorials for ASM, but can i ask why the move from C??

hi LG,
This what Ritesh said in his opening post.
I was reading data sheet and want to learn Timer0 in assembly
and why not.?
E

 

[Ian Rogers]

Ritesh!! I've posted a simple interrupt article.... Any comments would be well received..

Just click "Articles" on the menu banner..