Tool/software: Code Composer Studio
WIthIn the SimpleLink tool chain and MSP432 driverlib, wdt_a.h:
//*****************************************************************************
//
// The following are values that can be passed to the clockSelect parameter for
// functions: WDT_A_watchdogTimerInit(), and WDT_A_intervalTimerInit().
//
//*****************************************************************************
#define WDT_A_CLOCKSOURCE_SMCLK (WDT_A_CTL_SSEL_0)
#define WDT_A_CLOCKSOURCE_ACLK (WDT_A_CTL_SSEL_1)
#define WDT_A_CLOCKSOURCE_VLOCLK (WDT_A_CTL_SSEL_2)
#define WDT_A_CLOCKSOURCE_XCLK (WDT_A_CTL_SSEL_3)
#define WDT_A_CLOCKSOURCE_BCLK (WDT_A_CTL_SSEL_4)
PROBLEM: WDT_A_CTL_SSEL_4 is NOT defined in msp432p401r.h
#define WDT_A_CTL_SSEL_0 ((uint16_t)0x0000) /*!< SMCLK */
#define WDT_A_CTL_SSEL_1 ((uint16_t)0x0020) /*!< ACLK */
#define WDT_A_CTL_SSEL_2 ((uint16_t)0x0040) /*!< VLOCLK */
#define WDT_A_CTL_SSEL_3 ((uint16_t)0x0060) /*!< BCLK */
THEREFORE: I used WDT_A_CTL_SSEL_3 to select BCLK
// Set the WDA Timer for interval timer mode, 250msec interval.
// To be used as the interrupt source while in LPM3
MAP_WDT_A_initIntervalTimer(WDT_A_CTL_SSEL_3, WDT_A_CLOCKITERATIONS_8192);
