I have built an SBC based on the EVM3530 reference design, and it has been working great with the OMAP3530 processor. I am currently trying to get the same design to work with the DM3730, but I am seeing some strange behavior. Here is what I am observing:
* Board uses Micron 200MHz 32-bit LPDDR, 2Gb NAND flash
* Can successfully load XLDRUART.nb0 using pserial.exe over UART3
* Can successfully transfer xldr+eboot file over XModem, no errors writing to flash. Debug serial port output shows flash statistics, such as number of blocks written, etc.
* Restart board, but it does not read the image from NAND flash. Instead, it ends up outputting the ASIC ID over UART3
So it seems to me that the processor, NAND and Flash would have to be working to get this far (please correct me if I'm wrong).
The strange behavior I'm seeing has to do with the SYS_BOOT inputs - I added a debug output line after the flash write that shows the contents of the CONTROL_STATUS register, and it shows SYS_BOOT as 0x3F. This value is incorrect, I have it set up through pullup/pulldown resistors so that SYS_BOOT[4] = 0 and SYS_BOOT[3:0] = 1, so the correct value should be either 0x2F or 0x0F depending on the value of SYS_BOOT[5]. I have tried changing the pullup/pulldown configurations in several different ways, but it always reports 0x3F. I did a double-check with a board that still has the OMAP3530 on it, and it reports the correct value.
So I'm confused as to why the SYS_BOOT values would all be reported incorrectly as high. Is there a scenario where improper initialization of the processor can cause the SYS_BOOT values to be read incorrectly? Any other ideas that might help me figure out what's wrong? Again, this is a board that has been working properly, so the design is alright at least for the OMAP3530. Any help will be greatly appreciated.
