Hi,
I want to use the MPU in the supervisor state.
The MPU works in the user state (by detect the MPU access Error interrupt on violation access set for the test), but when I try in supervisor state the MPU access error interrupt does not append whereas the MPUSEL_SVSEN was set to 1 as defined in the datasheet.
I tried to configure the MPU with and without the MPUSEL_SVSEN set to 1, but there is no effect.
Why the MPU access error interrupt does not append in the supervisor state ?
Example of MPU configuration :
#define Start_Shared_Data1 __SEG_START_SHARED_DATA1
#define End_Shared_Data1 __SEG_END_SHARED_DATA1
#define CPU_S12 0x40
#define CPU_XGATE 0x20
#define WRITE_DISABLE 0x80
#define EXECUTE_DISABLE 0x40
/* Initialization of Memory Protection unit */
//setReg8(MPUSEL, 1 | MPUSEL_SVSEN_MASK); /* Select Descriptor num. 1 */
setReg8(MPUSEL, 1); /* Select Descriptor num. 1 */
U32Tmp_LowAdrress = (UINT32)Start_Shared_Data1;
U32Tmp_HighAdrress = (UINT32)End_Shared_Data1;
setReg8(MPUDESC2, ((UINT8)(U32Tmp_LowAdrress >> 3)));
setReg8(MPUDESC1, ((UINT8)(U32Tmp_LowAdrress >> 11)));
setReg8(MPUDESC0, (CPU_S12 | ((UINT8)(U32Tmp_LowAdrress >> 19))));
setReg8(MPUDESC5, ((UINT8)(U32Tmp_HighAdrress >> 3)));
setReg8(MPUDESC4, ((UINT8)(U32Tmp_HighAdrress >> 11)));
setReg8(MPUDESC3, (WRITE_DISABLE | EXECUTE_DISABLE | ((UINT8)(U32Tmp_HighAdrress >> 19))));
And after this configuration is set :
// Enable MPU in supervisor state
MPUSEL_SVSEN = 1;
If I change "Enable MPU in supervisor state" for "Set the CPU in User State" as follow, the MPUaccess error interrupt appends correctly as I want.
// Set the CPU in User State
asm("TFR CCRH,A");
asm("ORAA #128");
asm("TFR A,CCRH");
If you have an idea, you are welcome.
Thanks.
Guillaume.
