I am developing an application on LPC2138.
I prepared prototype using a standard development board. After completion, I shifted to final board.
But I am not able to download any program my LPC2138.
Connections are correct. I compared with my development board and checked every single pin. Voltage difference at VCC and VSS is 3.3V. Reset pin is high. Crystal is supplying fine square wave.
My final doubt is on Chip. I might have purchased a faulty or Fake LPC2138.
Is there any way to identify that Chip is good and I am missing something in programming.
P.S.: I grounded BSL pin, RESET the circuit. Ideally it should go in Bootloader and if I send "U" it should return "?". This happens on my development board but no response from final board.
Best Answer
It's unlikely your part is counterfeit, especially if you purchased it from a reputable distributor. Have you verified the following from this datasheet:
How is your RESET pin pulled high, what value resistor?
Detecting Counterfeits
There are companies you can send a part to and have it tested, American Counterfeit Detection is one such company.
Some of the signs to look for are:
This is a great resource for identifying counterfeit parts by visual inspection: Detection of Counterfeit Electronic Components
The following pictures show chips that have been sanded. Normally when a chip is molded it will not have any scratch marks.
Here you can see a marking that is easily wiped off.
Here you can see that they have attempted to re-stamp over the existing stamp.
Aside from a external visual inspection, here are some other methods used:
Integra Counterfeit IC Detection Methods: