CCS/MSP430FR2433: How to fix MSP430 ISR location

Hi, 

To fix the ISR function address, insert following directive under the #pragma vector = xxxx_VECTOR

• #pragma CODE_SECTION (ISR_symbol , "section name ")

Then define the section name in the linker file and the section is assigned to a dedicated memory area with your defined address. Please make sure the length is enough to fill the ISR. 

Thanks, 

Lixin

Hi, 

For more detailed demonstration, I can described this solution more detailed. 

Two steps:
1) In the formal linker file, define the new MyFRAM and MySection in the MEMORY{...}. Here is an example: 

     FRAM : origin = 0x8000, length = 0x1000             // note: the FRAM length will be changed due to MyFRAM occupies the FRAM space.
     MyFRAM : origin = 0x9002, length = 0x6F70        // note: the new defined section’s length is for the ISR which length needs to cover the ISR function content

2) In the linker file, define the new section .MySection and assign it to the new MyFRAM memory space. 

    .MySection : {} > MyFRAM

3) Add "#pragma CODE_SECTION (ISR function name, "new_section")" before the interrupt function in the user code. Here is an example to assign TB1_B0 interrupt ISR function to address .MySection which is defined in the linker file.

    #pragma vector = TIMER1_B0_VECTOR
    #pragma CODE_SECTION (Timer1_B0_ISR, ".MySection");
    __interrupt void Timer1_B0_ISR(void)
    {
     …
    }

With these 3 steps, you can assign the fixed address to the interrupt vector table in 0xFF80~0xFFFD so that the BSL password will be fixed. 

Thanks, 

Lixin 

Hi, 

Above method will need to calculate the ISR size when defining the memory section for ISR. There is also side-effect for compiler code size optimization for MCUs with small memory size. So we have another method to fix the BSL password for your optional choice: 

It is to use the function of set the register SYSRIVECT=1 to map the interrupt table to the top area of RAM. 

1) In the linker file, define new memory to map the interrupt vector table to this new FRAM area except reset vector. After code building, the interrupt vector will be in this new area.

2) In the user code, copy the interrupt table to RAM top area, and set the register SYSRIVECT=1. 

3) Change the content of 0xFF80 ~ 0xFFFD to assign BSL password (this area will not be changed by code building since there is new defined interrupt vector are). Since the reset vector 0xFFFE will be fixed after user code structure settled down, the BSL password will be fixed. 

There is no detailed description for how to change the linker file. We will have this in the future. 

Thanks, 

Lixin 

Hi Lixin,

We are flashing MSP from a host processor through BSL UART. We have already integrated and tested the processor side BSL flashing application.

Hi Lixin,

Yes it is helpful, I am working on Permanent BSL PW implementation by referring your demo. Thanks for your support.

Hi, Varkey, 

Glad to hear the good news. 

If my answers helped you to resolve your questions, could you please click on "This resolves my issue" button? 

Thanks, 

Lixin