We are using MPC8321 freescale microprocessor in one our boards. We are using NOR Flash M29DW323DT, from Numonyx (now Micron) as the boot flash. We are using Code warrior utility to program/access the flash. We are stuck at the first step of programming flash. Flash is not getting accessed properly.
As you may be aware that most of the flashes use CFI (Common Flash Interface) commands for various processes like program, erase, etc. A command consists of a sequence of writes including one or more steps. e.g in M29DW323DT, to put the flash in CFI Query mode the command is
Write Memory XXXX0055 with 0x00000098; this includes only one step of writing.
In contrary, programming/erase processes include three successive writes to put the flash in Programming/Erase mode.
It is observed that in our board, the flash is not able to take back to back writes. So for the commands which include only one write cycle, e.g Putting it in CFI query mode, it works and gives satisfactory outputs. But for commands like Program which includes 3 successive writes, it is failing.
Please suggest what could be the reason?
We have downloaded the flash driver from its respective website and executing the program source code through Code Warrior Debug Utility.