Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

avr external crystal defining problem?

Status
Not open for further replies.
O

omid_juve

Full Member level 1
Joined
Jul 1, 2007
Messages
97
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
1,990
atmega16 + external crystal

how can i define the fusebit of atmega16 for working with external 16M crystal?
every time that i define the fusebits for working with external crystal my programmer doesn`t recognize atmega 16 any more .
should i place first the crystal and then program the fusebits or first program the fusebits and then place the crystal . also i should say that for using the atmega16 with external crystal i program the cksel0-3=1111
please guide me in this problem.
 

program avr with crystal

Yes, you have place the crystal and then program the fuse bits.

dont forget to add two capacitors.

Regards
Nandhu
 

external crystal for atmega16

i should say that i do this but sometimes it will program and another it cant be programmed and it will be unrecognized for all time .
can you tell me the exact value for capacitor that i should use ?
 

ckopt in bascom

Hi
u must take care that 1 means unprogramed bit,in pony prog if if i get a sequence 1111 to define an external crystal with 16mhz,i will keep all bits check boxes umarkded,meaning unprogramed,as a marked chek box in pony prog means programed i.e bit is 0.u may look about this for your particular programmar.
shakeel
 

external crystal problem in atmega16

What program are you using to program the atmega?

You can always restore the atmega if the CLSEL fuse is corrupt by hooking up an oscillator (not a crystal) to the XTAL1 pin. Then reprogramming the fuse. Frequency does not matter.
 

i use bascom stk200/300 programmer
 

Will you be driving another clock source with XTAL2?

try programming
CKSEL = 0
CKOPT = 1

I use this option on an atmega8515 for external clock,
which is very similar device to the atmega16.

Look at page 23 of the datasheet.
 

if i program ckopt=0 then does it really need external cap for programming
 

This excellent article from avrfreaks.net explains the different clock sources you may use with an AVR, how to set them up and what fuse bits to set.

**broken link removed**
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top