17.5.7.1.1.2 ONFI 2.2 Parameters (Not Recommended)

In case no valid header is found, the Boot Program checks if the NAND Flash is ONFI-compliant, sending a Read Id command (0x90) with 0x20 as parameter for the address. If the NAND Flash is ONFI-compliant, the Boot Program retrieves the following parameters with the help of the Get Parameter Page command:
  • Number of bytes per page (byte 80)
  • Number of bytes in spare zone (byte 84)
  • Number of ECC bit corrections required (byte 112)
  • ECC sector size: by default, set to 512 bytes; or to 1024 bytes if the ECC bit capability above is 0xFF
By default, the ONFI NAND Flash detection turns ON the usePmecc parameter, and the ECC correction algorithm is automatically activated.

Once the Boot Program retrieves the parameter, using one of the two methods described above, it reads the first page again, with or without ECC, depending on the usePmecc parameter. Then it looks for a valid code programmed just after the header offset 0xD0. If the code is valid, the program is copied at the beginning of the internal SRAM.

Note: Booting on 16-bit NAND Flash is not possible; only 8-bit NAND Flash memories are supported.