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Re: Turning off interrupts in ISR

 by stube40 ¦  Mon Aug 22, 2011 9:34 pm ¦  Forum: MSP Microcontrollers ¦  Topic: Turning off interrupts in ISR ¦  Replies: 2 ¦  Views: 3022

I was wondering - is it necessary to manually disable/enable interrupts as I currently do, or does IAR automatically look after this for you when it compiles hence making my calls to __disable_interrupt() and __enable_interrupt() redundant? Read the user guide for the particular MSP430 family you a...

Turning off interrupts in ISR

 by stube40 ¦  Sun Aug 21, 2011 6:00 pm ¦  Forum: MSP Microcontrollers ¦  Topic: Turning off interrupts in ISR ¦  Replies: 2 ¦  Views: 3022

My interrupt service routines generally look like this: #pragma vector = PORT1_VECTOR __interrupt void PORT1_ISR(void) { __disable_interrupt(); // Disable global INTs so nothing can interrupt this ISR // General content of ISR __enable_interrupt(); // Re-enable global INTs } I was wondering - is it ...

Re: Trying to debug a weird reset issue on MSP430F2274

 by stube40 ¦  Sun Aug 21, 2011 5:48 pm ¦  Forum: MSP Microcontrollers ¦  Topic: Trying to debug a weird reset issue on MSP430F2274 ¦  Replies: 16 ¦  Views: 6671

@gm - I am powering the I2C bus through a FET

Re: Trying to debug a weird reset issue on MSP430F2274

 by stube40 ¦  Sun Aug 21, 2011 5:43 pm ¦  Forum: MSP Microcontrollers ¦  Topic: Trying to debug a weird reset issue on MSP430F2274 ¦  Replies: 16 ¦  Views: 6671

Hey guys - some great advice there! I had the weekend off, but I'm back onto it now and will report back with any new findings.

I liked the idea of toggling a port immediately at start up!!

No worries with "hijacking" the thread - it's all related and I don't mind at all.

Re: Trying to debug a weird reset issue on MSP430F2274

 by stube40 ¦  Thu Aug 18, 2011 11:06 pm ¦  Forum: MSP Microcontrollers ¦  Topic: Trying to debug a weird reset issue on MSP430F2274 ¦  Replies: 16 ¦  Views: 6671

@pabigot - it doesn't look like the MSP430F2274 has the SVS feature. It doesn't have a SVSCTL register defined for it.

Re: Trying to debug a weird reset issue on MSP430F2274

 by stube40 ¦  Thu Aug 18, 2011 9:14 pm ¦  Forum: MSP Microcontrollers ¦  Topic: Trying to debug a weird reset issue on MSP430F2274 ¦  Replies: 16 ¦  Views: 6671

I put a scope on Vcc and found that it is dropping to 2.5V when I switch the I2C rail on (ie when the reset problem happens). I haven't found the part in the data sheet which tells you how low Vcc can go, but I'm thinking it must be at least 2.2V. Hence, could this be a brown-out issue? Also, I decl...

Re: Trying to debug a weird reset issue on MSP430F2274

 by stube40 ¦  Thu Aug 18, 2011 9:07 pm ¦  Forum: MSP Microcontrollers ¦  Topic: Trying to debug a weird reset issue on MSP430F2274 ¦  Replies: 16 ¦  Views: 6671

I don't see where your reset line is being pulled high. It appears to be floating in your schematic. I believe that the 47K should go between your +V rail and the TDIO line and the cap should go between the TDIO line and ground. Yes, you are absolutely right. I modded the board to change to a 47k p...

Re: Trying to debug a weird reset issue on MSP430F2274

 by stube40 ¦  Thu Aug 18, 2011 4:20 pm ¦  Forum: MSP Microcontrollers ¦  Topic: Trying to debug a weird reset issue on MSP430F2274 ¦  Replies: 16 ¦  Views: 6671

@flll_freak - I put a breakpoint on the line before cstart and it never fires. I have two decoupling caps, C20 and C21, both 100nF and right next to the chip as you can see from the PCB and schematic below. I will test you theory to go without the USB debugger attached and report back. @pabigot - go...

Trying to debug a weird reset issue on MSP430F2274

 by stube40 ¦  Tue Aug 16, 2011 10:35 pm ¦  Forum: MSP Microcontrollers ¦  Topic: Trying to debug a weird reset issue on MSP430F2274 ¦  Replies: 16 ¦  Views: 6671

I'm trying to debug a weird issue by where my firmware resets itself whilst running on a MSP430F2274 - that is, it returns to the first line of assembler code labelled 'cstart_begin' in the disassembly. If I put a breakpoint on the line of assembler code previous to cstart_begin, it never fires - he...