Hi,
We have a problem to program LPC1768 MCU with the TFBGA100 package. Keil uVision software with the ULINK2 JTAG programmer is used to program and debug. We obtain the following error message «Error: Flash Downloaded failed - "Cortex-M3"» when downloading software to the MCU. According the log the flash erase is going okay but the flash write operation is aborted with the error.
If we use the same Keil uVision software and the ULINK2 JTAG programmer with the LPC1768 with the LQFP100 package. In this case the MCU is correctly programmed with the same software setting and binary files.
We try to use flash sector erase instead of full flash erase but have the same error during the programming.
Thank you in advance!
Sounds like it's got some issue with verifying the data written.
Perhaps there is a wiring consideration with the BGA package you have overlooked? Can you X-ray and confirm there are no voids in the solder balls, wicking from via-in-pad?
How about trying to enter the debugger without doing a flash update and doing some basic probing of memory? Seeing 0xFF? Testing code in RAM? Try a J-Link?
It doesn't sound like an issue with the package but an issue with the circuit.
Hi Pier!
Thank you for you reply.
We have some more detailed analysis of the JTAG signals for the MCU. JTAG signal sequence in the case of programming failure is two time shorter that in the case of correct MCU programming process (we compare the results with MCU on the MCB1700 evaluation board). Visual inspection of the first JTAG burst shows that input/output signals are quite similar in the good and bad programming cases. It seems that JTAG interface is okay for given circuit. design.
Can any other MCU pins except the JTAG/power/ground have an impact on the onchip Flash programming process.
Alexey