CCS/MSP430FR5969: The instruction SR_SP_OFF()

Minh Lam

Tool/software: Code Composer Studio

Dear all,

I'm wondering whether implementing the following instruction will disable interrupts or just exit LPM4. The program has encountered LPM4 and enable general interrupt previously with the instruction: BIS #LPM4+GIE, SR

BIC.W #(LPM4), SR_SP_OFF(SP)

Thank you very much.

over 8 years ago

0 Caleb Overbay over 8 years ago

TI__Genius 15370 points

Hi Minh,

The line of code you've posted above will only exit LPM4 and not disable interrupts. You can verify this in CCS by executing the line of code after setting the GIE bit and then viewing the SR register in the register view while debugging.

Best regards,
Caleb Overbay

0 Minh Lam over 8 years ago in reply to Caleb Overbay

Intellectual 750 points

Dear Caleb,

Thank you for your answer. That solved my question. Where can I get the symbols like 'SR_SP_OFF" because they seem to be special and pre-defined ones?

By the way, I still don't understand clearly the symbolic mode, for example with the questioned code. If possible please give me a clear explanation. Thank you very much for your kind support.

0 Caleb Overbay over 8 years ago in reply to Minh Lam

TI__Genius 15370 points

Hi Minh,

I'm not familiar with the SR_SP_OFF symbol and it's most likely application specific. You can find an example of exiting LPM4 in assembly language here:

In this example you can see that LPM4 is exited from the ISR with this line of code: "bic.w #LPM4,0(SP)". You can also find many other C and assembly language examples in the TI resource explorer.

Finally, I would recommend reading section 4.4.3 of the the MSP430FR58xx, MSP430FR59xx, and MSP430FR6xx Family User's Guide. Let me know if you have any further questions!

Best regards,

Caleb Overbay

0 Minh Lam over 8 years ago in reply to Caleb Overbay

Intellectual 750 points

Hi Caleb,

Thank you very much.

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CCS/MSP430FR5969: The instruction SR_SP_OFF()