Posted on November 20, 2017 at 20:53Dear all,
I am trying to set-up a new board using an stm32H743.
In my tests, I initialized the MPU in order to use the cache L1 with the Flash.
When I initialize the MPU to use the cache, the results are really impressive (about 1.8 faster than without L1).
Unfortunately, the system is not stable; I often have 'hardfault' situation.
Any suggestion of how to use L1 with the internal Flash?
Here is my initialization code before activating the cache.
Best regards
Edo
...
// New attributes for the FLASH area (0x08000000)
// Change the attribute only in the executable area
MPU->CTRL = 0x00000000; // Disable the MPU
MPU->RNR = 0x00000000; // Region 0
MPU->RBAR = 0x08000000 | (1<<4) | (0<<0); // Address, valid & region 0
MPU->RASR = (0<<28) // Instruction fetches enabled
| (6<<24) // Unprivileged read-only
| (0<<19) // TEX: 000 Memory attribute
| (1<<18) // S: 0
| (1<<17) // C: 1
| (0<<16) // B: 0 un-sharable, Normal, outer and inner write-through,
// no write allocate
| (0<<8) // Corresponding sub-region is enabled
| (20<<1) // 2-MB
| (1<<0); // Region enable
MPU->CTRL = (1<<2) // Enable the usage of all the default map
| (1<<1) // MPU is enabled during the fault
| (1<<0); // MPU enabled
MEMO_SYNC_BARRIER;
DATA_SYNC_BARRIER;
INST_SYNC_BARRIER;
...
#stm32h7
