I'm trying to generate a power-up clear (PUC) on my MSP430F149 from
software, and to do so without setting the WDTIFG bit in IFG1.  That
last piece is important because I'd like use WDTIFG to distinguish
between watchdog-generated and software-generated PUCs.

I had hoped to accomplish this with an FCTLx security key violation,
but I've found that this action always sets WDTIFG in addition to KEYV
in FCTL3.  (SLAU049D does not mention this behavior.)  I can work
around this by testing both WDTIFG and KEYV, but I find this solution
to be rather unsatisfying.

Does anyone know if there's a way to generate my PUC without setting
WDTIFG?

Noah

Set a flag in RAM to a special value indicating you are doing a forced
WDT reset.  Check it and the WDTIFG at powerup, then immediatly clear
the flag.

-Bill Knight
R O SoftWare


On Thu, 03 Jun 2004 19:33:35 -0000, Noah Treuhaft wrote:

>I'm trying to generate a power-up clear (PUC)
on my MSP430F149 from
>software, and to do so without setting the WDTIFG bit in IFG1.  That
>last piece is important because I'd like use WDTIFG to distinguish
>between watchdog-generated and software-generated PUCs.

>I had hoped to accomplish this with an FCTLx
security key violation,
>but I've found that this action always sets WDTIFG in addition to KEYV
>in FCTL3.  (SLAU049D does not mention this behavior.)  I can work
>around this by testing both WDTIFG and KEYV, but I find this solution
>to be rather unsatisfying.

>Does anyone know if there's a way to generate
my PUC without setting
>WDTIFG?

>Noah

In one of my designs I used this...

WDTCTL = 0xFFFF

As per the User Guide...

  A system reset (PUC) is generated if any value other then 05Ah is written to
the high byte of address 0120h.

  ----- Original Message ----- 
  From: Noah Treuhaft 
  To: msp430@msp4... 
  Sent: Thursday, June 03, 2004 3:33 PM
  Subject: [msp430] Software-generated power-up clear without setting WDTIFG


  I'm trying to generate a power-up clear (PUC) on my MSP430F149 from
  software, and to do so without setting the WDTIFG bit in IFG1.  That
  last piece is important because I'd like use WDTIFG to distinguish
  between watchdog-generated and software-generated PUCs.

  I had hoped to accomplish this with an FCTLx security key violation,
  but I've found that this action always sets WDTIFG in addition to KEYV
  in FCTL3.  (SLAU049D does not mention this behavior.)  I can work
  around this by testing both WDTIFG and KEYV, but I find this solution
  to be rather unsatisfying.

  Does anyone know if there's a way to generate my PUC without setting
  WDTIFG?

  Noah



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