Hi @aiyayabeibei
S32K312 has following flash blocks (see „Table 92 Flash block configuration“ in the reference manual)
Block 0 – Code flash 1MB at 0x0040_0000 - 0x004F_FFFF
Block 1 – Code flash 1MB at 0x0050_0000 - 0x005F_FFFF
Block 2 – Data flash 128KB at 0x1000_0000 - 0x1001_FFFF
If FullMem HSE FW is installed, the memory shrinks to following (because the rest is allocated exclusively for HSE):
Block 0 – Code flash 1MB at 0x0040_0000 - 0x004F_FFFF
Block 1 – Code flash (1MB-176KB)at 0x0050_0000 - 0x005D_3FFF
Block 2 – Data flash (128KB-40KB) at 0x1000_0000 - 0x1001_5FFF
Now, when you write the lock bits, it is necessary to keep the bits covering HSE space set. This is the key point. If you try to write a value where even one bit covering HSE space is cleared, bus error is returned.
So, when using sector protection (last 256KB of each block), we can write any number to PFCBLK0_SPELOCK because Block 0 is not affected by HSE.
In case of Block 1, the situation is different. Last 176KB is occupied by HSE, so only 80KB left. 80KB means that it’s 10 sectors. If we want to unlock all of them, we can write:
PFCBLK1_SPELOCK = 0xFFFFFC00;
This will pass because we kept all HSE bits set. And you can write anything to lowest 10 bits.
In case of data flash (Block 2), there’s 88KB. To unlock all of them:
PFCBLK2_SPELOCK = 0xFFFFF800;
Super sectors are applicable only for Block 0 and 1. HSE does not affect first 768KB of those 1MB blocks, so there are no issues here and you can write anything to PFCBLK0_SSPELOCK and PFCBLK1_SSPELOCK.
Data flash (Block 2) has less than 256KB, so super sector has no effect here.
Regards,
Lukas
