WDOG and interval timer

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1

Hello Forum members,

I am using MSP430F1611 with CrossStudio. I want to implement a real time interrupt which will be executed after certain intervals, similar to RTI in case of HC11 controller. In case of MSP430, I can implement this using WDOG as interval timer. But looking at WDTTMSEL bit of WDTCTL register, I can use WDOG of MSP430 only in one the mode - either WDOG or interval timer. Not both of them at a time. Please clarify my understanding. Also how to implement real time interrupt in MSP430 along with WDOG?

Thanks in advance.

2

Using WDT as an interval timer, there are only six different settings.

/* WDT-interval times [1ms] coded with Bits 0-2 */
/* WDT is clocked by fSMCLK (assumed 1MHz) */
#define WDT_MDLY_32         (WDTPW+WDTTMSEL+WDTCNTCL)                         /* 32ms interval (default) */
#define WDT_MDLY_8          (WDTPW+WDTTMSEL+WDTCNTCL+WDTIS0)                  /* 8ms     " */
#define WDT_MDLY_0_5        (WDTPW+WDTTMSEL+WDTCNTCL+WDTIS1)                  /* 0.5ms   " */
#define WDT_MDLY_0_064      (WDTPW+WDTTMSEL+WDTCNTCL+WDTIS1+WDTIS0)           /* 0.064ms " */
/* WDT is clocked by fACLK (assumed 32KHz) */
#define WDT_ADLY_1000       (WDTPW+WDTTMSEL+WDTCNTCL+WDTSSEL)                 /* 1000ms  " */
#define WDT_ADLY_250        (WDTPW+WDTTMSEL+WDTCNTCL+WDTSSEL+WDTIS0)          /* 250ms   " */
#define WDT_ADLY_16         (WDTPW+WDTTMSEL+WDTCNTCL+WDTSSEL+WDTIS1)          /* 16ms    " */
#define WDT_ADLY_1_9        (WDTPW+WDTTMSEL+WDTCNTCL+WDTSSEL+WDTIS1+WDTIS0)   /* 1.9ms   " */