MSP430FR2433: Declaring assembly language variable as persistent in RTC_Calendar.asm/RTC_Calendar.h

Jeevant Sah

Part Number: MSP430FR2433

Hi,

I am trying to run the RTC Calendar(Link) in MSP430FR2433 MCU. I was wondering if I can declare assembly language variable as persistent so that the variable from RTC_Calendar.asm/.h can stay all the time in memory even after reset with last known state.

Variable I am trying to make persistent are:

;Variables
.def TI_day
.def TI_FebDays
.def TI_hour
.def TI_dayOfWeek
.def TI_PM
.def TI_second
.def TI_year
.def TI_minute
.def TI_month
.def TI_dayLightZone
.def TI_dayLightSavings

Thanks

Jeevant Sah

over 3 years ago

+1 Evan Lew over 3 years ago

TI__Genius 10060 points

Hi Jeevant,

In the example you are referencing similar variables are already declared persistent in main.c. If you think you need to declare a variable persistent from a .asm file, you can look at ctpl_low_level.asm in the same project for reference (look for the .usect ".TI.persistent" directive). However, I would avoid writing assembly if you can help it. Declaring variables persistent from C is much easier.

Regards,

Evan

0 Jeevant Sah over 3 years ago in reply to Evan Lew

Prodigy 100 points

Hi Evan,

Thanks for the solution, I would like to ask one more things If I declare a variable persistent in assembly and use it in C using extern variable, will I be able to use that extern variable as a normal persistent variable in C and change its value using C?

0 Evan Lew over 3 years ago in reply to Jeevant Sah

TI__Genius 10060 points

I believe so, but I would test it to be sure.

Evan

0 Jeevant Sah over 3 years ago in reply to Evan Lew

Prodigy 100 points

Hi Evan,

Thanks for the solution, it worked as expected.

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MSP430FR2433: Declaring assembly language variable as persistent in RTC_Calendar.asm/RTC_Calendar.h