I have a custom Blackfin 533 board with M29W320 FLASH memory mostly based on the EZ-KIT circuit. A single SDRAM is mapped into lower address space. Because the application demands minimum power, I have three power supplies, VDDEXT, VDDINT and third supply for 3.3V. The FLASH device and SDRAM are on 3.3V rail. When the processor goes into Hibernate mode it shuts down the 3.3V rail (the shut down is based on VR_OUT). When the processor comes out of hibernation it restores the 3.3V rail and attempts to reboot (based on SYS_CFG). The processor boots correctly when battery power is applied but refuses to boot correctly when coming out of hibernate mode. The 3.3V rail restores quickly but the processor still hangs waiting for something, it can hang for more than 20 secs but often eventually boots. I cant find much literature on the specifics of the boot sequence with the FLASH device but would appreciate if you can describe exactly what the processor does after VDDINT reaches the correct value for processor execution.
Many thanks, any help is appreciated