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.
I agree with Brian -- I have witnessed tantalum capacitors explode several times. Note, they will explode in two conditions. The first is if they are put on backwards (i.e., the polarization is reversed). In my experience, this tends to be less "explosive" -- at least the capacitor itself...
99% of the time, USART issues are due to clocking problems. What are your fuse settings (with respect to your clock source)? For example, if you have set the fuses to use an external crystal, is that crystal present? Is the divide by eight fuse programmed or unprogrammed?
Secondly, it looks...
Cheaper option: AVR Studio 4 (free software ide) with AVRISP MKii -- cheaper than a dragon. It can't do debugging (like JTAG) or high voltage programming (like dragon), but it is the most inexpensive option, and works very well for programming purposes only.
kandhu,
If you are using a common Atmel programming software (i.e., programming the chip from AVR Studio), the first step of the "programming process" is to erase the chip, including EEPROM. To avoid this, you need to change one of your fuses. In the fuse high byte, bit 3 (0 indexed), you...
Also, try AVRFreaks. They tend to be a little C heavy, but there is definitely info on assembly programming as well. In particular, go to the tutorials portion of the forum:
View Forum - AVR Tutorials :: AVR Freaks
Are you providing the chip with an external clock? If you set the fuse so that the chip runs off an external clock, and no clock is present, you will no longer be able to communicate with the chip.
Try providing a square wave (1MHz should work) on the XTAL1 pin of the micro. Then try...
He was referring to how thick the dielectric is, not really meaning the glue.
DXF is just a standard drawing file type. It can be opened with DXF viewers available online (freeware). I know Solidworks can open .dxf files, I have never used Autocad, so I don't know.
I create my fabrication...
Both. Sort of. When impedance controlled lines are required, it is best to start thinking about them as early in the process as possible. If you haven't picked a board house yet, you can always do what I mentioned earlier -- use the constraint editor to force all lines that will be impedance...
I have not done a board with DDR. I would look at the data sheet for the chip in question and see what it recommends, rather than just trusting a reference design of questionable provenance.
The naming convention for layers I was using was strictly physical. I.e., "Layer 1" refers to the top...
In 99% of cases, you must have planes on either side of an internal signal layer with impedance controlled lines. Furthermore, unless you want to greatly complicate your math, the dielectric thickness must be the same on either side of the layer in question. For external (microstrip) layers...
It is unusual to say, "I want a 5 mil trace to be 50 ohms." Unless you actually have a reason for fixing your trace width (i.e., fanning out from a tight BGA), the easiest way to obtain a controlled impedance line is by varying the width. The second parameter that can be varied is substrate...
That is not really what I am talking about. I have a programmer -- an AVRISP mkII that I will use to program the board. I am just concerned that I have PDO and PDI flipped.
So I found out the hard way that the ATMEGA1281 does not use the SPI pins for ISP (what's that pnemonic about how to spell "assume"?).
I have a second design that I am ready to send to the board house, but would like to confirm that I actually have the ISP pins identified correctly. I am using...
Try this blog:
**broken link removed**
... and then look at parts 2 - 10. It is pretty complete. Cadence specific examples can be found either by googling or in a book called Complete PCB Design Using OrCAD Capture and PCB Editor, by Kraig Mitzner.
Check with your board house for their...
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
