Hi, I am going to overclock Atmega16L to 12MHz. I can do that when the JTAG header is attached. However, when it is detached, the program seems to be not working. I have tried to shut down the power of the emulator and it still works when the JTAG header is attached. I do not understand why this strange case happens. Could anyone talk to me why this happens? As I need to use 3.3V, I need to use Atemga16L.
Overclcok AtmegaL
Started by ●January 29, 2006
Reply by ●January 29, 20062006-01-29
eeh wrote:> I am going to overclock Atmega16L to 12MHz. I can do that when the JTAGYou are so 3L33T. RaDiCaL To THe MaX, DuDe.> it still works when the JTAG header is attached. I do not understandThe JTAG might be holding down reset a bit longer than normal. Remove JTAG, power up, use wire to reset device. Does it work?
Reply by ●January 29, 20062006-01-29
larwe wrote:> eeh wrote: > > > I am going to overclock Atmega16L to 12MHz. I can do that when the JTAG > > You are so 3L33T. RaDiCaL To THe MaX, DuDe.Yeap, considering that they are plenty of Atmega16* at 16MHz, and cheaper than 8MHz as well. If you overclock a 16MHz part to 32MHz, that might be intereresting.
Reply by ●January 30, 20062006-01-30
> The JTAG might be holding down reset a bit longer than normal. > > Remove JTAG, power up, use wire to reset device. Does it work?I add RC at the reset pin which are 1M Ohm and 0.1uF respectively. But it has no improvement and is stll not working.
Reply by ●January 30, 20062006-01-30
Reply by ●January 30, 20062006-01-30
Don't do it. Use a faster processor instead "eeh" <eehobbyist@yahoo.com.hk> wrote in message news:1138558119.023935.294880@o13g2000cwo.googlegroups.com...> Hi, > > I am going to overclock Atmega16L to 12MHz. I can do that when the JTAG > header is attached. However, when it is detached, the program seems to > be not working. I have tried to shut down the power of the emulator and > it still works when the JTAG header is attached. I do not understand > why this strange case happens. Could anyone talk to me why this > happens? As I need to use 3.3V, I need to use Atemga16L. >
Reply by ●January 30, 20062006-01-30
Reply by ●January 30, 20062006-01-30
i suggest you run a test over the complete temperature range. It might run overclocked at 25 degrees ,but may fail in a hot summer. Bad practice if you want a stable sytem. Johan "eeh" <eehobbyist@yahoo.com.hk> wrote in message news:1138634286.076967.253360@g14g2000cwa.googlegroups.com...> OK after adding 10uF decoupling cap at 3.3.V supply >
Reply by ●January 30, 20062006-01-30
What size cap did you have there before? And another question - what sort of power supply are you using - better stated maybe, how long are the wires that bring power to microcontroller? Neccessary filtering for a power supply always seems questionable. Hul eeh <eehobbyist@yahoo.com.hk> wrote:> OK after adding 10uF decoupling cap at 3.3.V supply
Reply by ●January 30, 20062006-01-30
Hul Tytus wrote:> What size cap did you have there before? And another question - what sort > of power supply are you using - better stated maybe, how long are the > wires that bring power to microcontroller? > > Neccessary filtering for a power supply always seems questionable. > > HulBefore that I used only two 0.1uF at the regulator. The board is small which is about 3 inches x 2 inches. The power supply is dc supply (5V) and the voltage passes a HT7533 linear regulator.