hi
we have a customed OMAPL138 board.
The board (let's call it BoardA) was soldered with the wrong type DSP(OMAPL138ZWTD4E), so we had to remove the wrong DSP and re-solder the right type DSP(OMAPL138ZWTD4). Because of the worry of weak solder, after re-solder, we confirm the PCBA good status with its UART output "BOOTME".
we want to download a user bootloader into the internal ram with UART by OMAP-L138_FlashAndBootUtils_2_40 tools to boot the board .
the problem is we can download user bootloader sucessfully to BoardA by UART,but when BOOTROM jump to the user bootloader, it can not even output a simple character by UART.
we did these works to check the board status:
1)considering the possibility of weak solder, we try to power down all other modules not needed in minimize system ,like DDR, SPI,.., just power on the PLL and UART we used, by setting PSC0 and PSC1, the result is same.
2)we check the downloaded image in PCBA's ram, they are exactly the same thing we download
3)we check the board status by debug GEL, it seems PC stay in user boot loader area.
4)we compare the peripheral modules stat after out bootloader running with BOOTROM running, keep they are same, the result is not changed
5)we also check the UART registers, find that the UART registers are not the data we want
6)if we do not put data on UART transmit buffer, we can blink a LED normally.
Now we are very confused, why this minimize image can not set UART correctly and output characters? Anyway, BOOTROM can communiate with host PC by UART successfully.
can someone provide some idea or advice on this weird problem?
if my description is not very clear and detailed, i can provide more detail.
thanks in advance
Jie