about crtstal oscillator

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#1
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what is the maximum frequency crystal oscillator we can connect to ATMEGA 32 mcu.

when i connect 4 Mhz crystal it's working .

when i connect 8  Mhz crystal it's working but not in proper way.

when i connect 16 Mhz crystal it's not working and when i connect it for code transfer it fail so what i do please help me

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What does the datasheet tell you?

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What  is the MCU supply voltage (at the MCU's power pins)?

 

Jim

Jim Wagner Oregon Research Electronics, Consulting Div. Tangent, OR, USA http://www.orelectronics.net

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balvendra wrote:

what is the maximum frequency crystal oscillator...when i connect 4 Mhz crystal...

 

An oscillator is not a crystal. Which are you using? You need to learn the difference or one day you will set your fuses wrongly.

'This forum helps those who help themselves.'

 

pragmatic  adjective dealing with things sensibly and realistically in a way that is based on practical rather than theoretical consideration.

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Brian Fairchild wrote:
An oscillator is not a crystal ... You need to learn the difference

This may help: https://e2e.ti.com/support/micro...

 

EDIT

 

See also: http://www.avrfreaks.net/forum/e...

 

 

#CrystalOscillator

 

Last Edited: Wed. Sep 27, 2017 - 08:41 AM
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5 volt

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this was mistook in typing i am using external crystal

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from data sheet i could not get idea about that so i am asking here

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At 5V a mega32 should run with a 16MHz crystal.

 

What value capacitors have you connected to the crystal?

 

What are your fuses set to?

'This forum helps those who help themselves.'

 

pragmatic  adjective dealing with things sensibly and realistically in a way that is based on practical rather than theoretical consideration.

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balvendra wrote:
from data sheet i could not get idea about that

Really??

 

surprise

 

 

EDIT: See also the sections titled, "Clock Sources" (p25) and "Crystal Oscillator" (p26) 

 

Page references to the 2503Q–AVR–02/11 document revision.

Last Edited: Tue. Jul 4, 2017 - 07:21 AM
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Capacitor - 22 pf
Fuse - EE OD

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I set fuse bit using eclipse like this

Attachment(s): 

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balvendra wrote:
Capacitor - 22 pf Fuse - EE OD

 

 

I'd be tempted to give the crystal a bit longer to start up. Unless I'm in a hurry I always use the slowest settings...

 

 

'This forum helps those who help themselves.'

 

pragmatic  adjective dealing with things sensibly and realistically in a way that is based on practical rather than theoretical consideration.

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Your picture shows CKOPT set to No.
.
It MUST be enabled for crystals of 8MHz and above or the drive is not strong enough for it to resonate.

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clawson wrote:
Your picture shows CKOPT set to No.
.
It MUST be enabled for crystals of 8MHz and above or the drive is not strong enough for it to resonate.

I had never programmed ckopt unless I need to drive other device with the same clock source or noisy environment.
.

I guess the OP is working with UART or time critical.
How can he be sure it's working or working but not in the proper way?

.

MG

I don't know why I'm still doing this hobby

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MicroGyro wrote:

How can he be sure it's working or working but not in the proper way?

 

Aha, I wonder if the OP means that his programming fails? In which case, are we looking at an ISP speed issue?

'This forum helps those who help themselves.'

 

pragmatic  adjective dealing with things sensibly and realistically in a way that is based on practical rather than theoretical consideration.

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22 pf capacitor is right value???
and i am using usbtiny so can it communicate with mcu at all frequency??

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balvendra wrote:
22 pf capacitor is right value???
and i am using usbtiny so can it communicate with mcu at all frequency??

You mean your usbtiny? Of course you can.
Set your isp clock 1/4 of your mcu clock.
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Brian Fairchild wrote:
Aha, I wonder if the OP means that his programming fails? In which case, are we looking at an ISP speed issue?

You are right :D
.
MG

I don't know why I'm still doing this hobby