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Set of noob questions !

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Hi all, I just started with msp430. I am very noob !!!


First question: How do I set the Status Register bits in C?


slau144j.pdf assembly example, setting CPUOFF and GIE bit:

; Enter LPM0 Example
; Exit LPM0 Interrupt Service Routine
But if I need set just the GIE bit, how do I do that ?
I dont want to use functions like __enable_interrupts(), I
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The intrinsics are used... e.g.


__bis_SR_register(GIE);  // set GIE bit

__bic_SR_register(GIE);  // clear GIE bit


Those work in MSPGCC, along with a few variations like _BIS_SR() and _BIC_SR() which might also work in TI's CCS IDE (not sure which one is supported by which though; I always use the __bic_SR_register() and __bis_SR_register() type of intrinsics since I use MSPGCC exclusively)

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  • 2 weeks later...

You can supply 5v & ground to the test points TP1 and TP3 beside the USB socket. 


If you really don't want to power from the USB then you might have to doctor the micro-usb cable to remove the +5v pin (or cut the wire).  The only time I've had to do that was on a Raspberry pi - to prevent a badly regulated powered USB hub from back-powering the Pi.

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