TMS570LC4357: TMS570LC4357 MPU issue

Hi Prasanna,

Is it possible to share your complete project, so that i can quickly debug it at my end?

And also, which board you are using, is it TI-specific board or custom board?

I never came across this kind of issue before, usually EMIF, i2c and SPI will operate independently only.

If you are not using TI-specific board then provide project where EMIF should work and SPI3 should not work. Because i can easily verify SPI3 behavior and can identify what went wrong.

And also, we have one internal AI which has access to all our internal database related to this device, when i feed your question to it i got some useful guidelines. Could you please also verify these suggestions once:

Issue Analysis

The TMS570LC4357 microcontroller's Memory Protection Unit (MPU) restricts access to memory regions based on configured permissions. When peripherals like EMIF and SPI3 need to access memory, they must have appropriate permissions in the MPU configuration.

Your issue occurs because:

• The MPU settings were optimized for EMIF operation
• SPI3 requires its own access permissions to function correctly
• Modifying settings for one peripheral affects the other

Solution Approach

You need to configure separate MPU regions for each peripheral:

1. Review Current MPU Configuration:

   • Identify which regions are currently configured for EMIF
   • Determine which memory addresses SPI3 needs to access

2. Configure Dedicated MPU Regions:

   • EMIF typically requires access to external memory regions
   • SPI3 requires access to its own register space (0xFFF7_3800 to 0xFFF7_3FFF)

3. Implementation Guidelines:

// Example MPU configuration for both peripherals
void configureMPU(void)
{
    // Configure region for EMIF (adjust addresses as needed)
    _mpuSetRegion(MPU_Region1, 0x60000000, 0x68000000, 
                  MPU_FULL_ACCESS, MPU_EXEC);
    
    // Configure region for SPI3 peripheral registers
    _mpuSetRegion(MPU_Region2, 0xFFF73800, 0xFFF73FFF, 
                  MPU_FULL_ACCESS, MPU_NO_EXEC);
    
    // Enable MPU
    _mpuEnable();
}

     4. Key Considerations:

• Ensure regions don't overlap inappropriately
• Set proper access permissions (read/write/execute)
• Verify region sizes are appropriate for each peripheral's needs

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Thanks & regards,
Jagadish.