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RTC on MSP430

Started by Vito Russo June 10, 2004
Hi!

I need a Clock on my MSP430F149. Now i'm using timerB as a clock. But when
the supply voltage supervisor reset the micro (and this happens often) i lose al
the data about the time and date. How can I avoid this?

I've heard about RTC stand-alone chips. Is there a cheap RTC?

Thank you and Good Bye

Vito   




Beginning Microcontrollers with the MSP430

It sounds like you have a basic circuit design problem. Either get a new 
supervisor chip, find out why it is resetting so often,  get a better 
power supply set up, or better still throw away the supervisor chip, 
I've never needed one on the '149 and have thousands of shipped
systems. 
An RTC should be the simplest thign to implement on the MSP430.

Al

Vito Russo wrote:
> Hi!
> 
> I need a Clock on my MSP430F149. Now i'm using timerB as a clock. But
when the supply voltage supervisor reset the micro (and this happens often) i
lose al the data about the time and date. How can I avoid this?
> 
> I've heard about RTC stand-alone chips. Is there a cheap RTC?
> 
> Thank you and Good Bye
> 
> Vito   
> 
> 
> 
> 
> 
> 
> .
> 
>  
> Yahoo! Groups Links
> 
> 
> 
>  
> 
> 


Hi Vito,
 
if you programming MSP in C language you must modify STARTUP file. In this
assembler file, which is automatically linked with your project, there is a RAM
initialisation routine that clear RAM after reset.
 
Goran

Vito Russo <vrusso@vrus...> wrote:
Hi!

I need a Clock on my MSP430F149. Now i'm using timerB as a clock. But when
the supply voltage supervisor reset the micro (and this happens often) i lose al
the data about the time and date. How can I avoid this?

I've heard about RTC stand-alone chips. Is there a cheap RTC?

Thank you and Good Bye

Vito   
		
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Ops, I believed the RAM is erased when the reset pin goes low. But I never
tested it..

I'll try to modify the startup file then (I've already modified it to
program a software firmware loader so I know the code you told me about)

Thanks a lot Goran!

Bye

Vito  
  ----- Original Message ----- 
  From: Goran Dragisic 
  To: msp430@msp4... 
  Sent: Thursday, June 17, 2004 2:13 PM
  Subject: Re: [msp430] RTC on MSP430


  Hi Vito,

  if you programming MSP in C language you must modify STARTUP file. In this
assembler file, which is automatically linked with your project, there is a RAM
initialisation routine that clear RAM after reset.

  Goran

  Vito Russo <vrusso@vrus...> wrote:
  Hi!

  I need a Clock on my MSP430F149. Now i'm using timerB as a clock. But
when the supply voltage supervisor reset the micro (and this happens often) i
lose al the data about the time and date. How can I avoid this?

  I've heard about RTC stand-alone chips. Is there a cheap RTC?

  Thank you and Good Bye

  Vito   
              
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