BootStrap problem, cannot boot.


I have made an interface board based on the DIGI development schematics for Wi-i.mx51. The core module works fine with the development board, but it did not boot on my board (no activity on the NAND flash memory). The power supplies are correct on every pins. I suspect the boot mode configuration which I modified the bootstrap schematics.

The modifications are
(1) I do not use any displays, so there is no schematics related to the delay and displays on my board. By this I mean, there is no schematics located on the top right of the boot strap of the development board. (the second thought told me that this may be the problem.)

(2) We don’t need boot_mode and boot_config dip switches (S8,S9) because we always boot from the default configuration which is from internal NAND flash memory.

(3) The following connections are left from the bootstrap of the development board.
3.1 BOOT_MODE0 is not connected (=S9.1 open).
3.2 BOOT_MODE1 is not connected (=S9.2 open).
3.3 DISP1_DAT14_BOOT is connected to 1kOhm to GND (Boot_config1 = High).
3.4 DISP1_DAT20 and DISP1_DAT21 is not connected (Boot_config1 = High).

Are there any other setting that I missed?

Hi again,

I found that I have not connected the !POR pin. It was floating which may cause the booting problem, so I added the 10K ohm pull-up resistor on the POR pin, but It is still not booting.