Hello.
We made a custom prototype board based on the AM335x Starter Kit EVM. Instead of AM3359 we are using AM3352. Instead of MT41J128M16 we are using the MT41J128M8 DDR.
We removed certain interfaces which were present (USB OTG, Ethernet, Audio, JTAG). The proper configuration for the RAM has not been done yet in software. I have yet to verify my pinmux configuration, but I don't think this is a problem at the moment as we kept the pin layout which is used for the Starter Kit.
In U-Boot I routed the serial output to UART1, which seems to work. When I compile for UART0, the output is on UART0, same values.
The boot configuration was kept, i.e. we are booting from an SD Card. The voltages incl VDD_MPU, CORE, VDDSHV?, reference voltage for DDR seem to be fine.
The problem is: the output we get on UART1 does not seem to make any sense, and seems like a random stream of bits. It is however constant, and is same on every (re)boot. I don't think this stream can help, but in any case, here it is: http://pastebin.com/ZKZRc86n. The stream lasts for about 20 ms.
Other interesting thing is the clock on the SD Card: There is a clock for 300 ms @ 100 Hz if I am not mistaken,, which then stops. Also, Signals on D0 and CMD appear for the same duration of time.
I also don't get a stream of C characters on UART0 TX. There was a stream of data I mesaured yesterday with oszi, but now the signal is only pulled high. I have a reason to believe the board is (half!?)dead, since the ROM is silent.. But why is there an output after the ROM boots, on a correct port!?!?
Can you provide me some pointers on what I can check next and what I am missing.
I am going do to the pinmux configuration/verification, and see what I need to change in the DDR configuration - it might be that the bootloader cannot be loaded into RAM. Meanwhile, maybe someone else can give a feedback what else I can look into before I start soldering stuff on a new board..
Thank you.
