MSP430 LaunchPad, DriverLib, TIMER_A and CCR0 Duration

Hello,

I am trying to determine the frequency of the TIMER_A with a given Capture/Control Register 0 (CCR0) value 0.

My understanding is that the frequency is (SMCLK)* (1/CLOCKSOURCE_DIVIDER)*(1/Number of Cycles)

My configuration:

• Clock source is SMCLK.  SMCLK frequency is 8MHz (¹),
• CCR0 value is 50000 decimal (0xC350).
• TIMER_A is set in continuous mode (TIMER_A_CONTINUOUS_MODE)
• "timer_a_ex2_continous ModeOperationWithCCR-Interrupt"
  • Src: MSP430ware/Libraries/Driver Library/MSP430F5xx_6xx/Example Projects/TIMER_A
  • The only change I made is this: replaced TIMER_A_CLOCKSOURCE_DIVIDER_1 with TIMER_A_CLOCKSOURCE_DIVIDER_16.

f =  (8 MHz)*(1/TIMER_A_CLOCKSOURCE_DIVIDER_16)*(1/50000) = 10Hz

When I execute the code I see the LED blink on and off with an estimated frequency of 0.80s.  I am using a simple timer on my phone to estimate the frequency.

Looks like I am off by one order of magnitude...

What am I missing?

I appreciate any help from the community?

With kind regards,

Electric Cowboy

References:

(¹) - "slau533b - MSP-EXP430F5529LP User's Guide.pdf" - page 45/61

(²) - "slau390c - Unified Clock System.pdf", Figure 1-1 UCS Block Diagram - page 3/29.

Code excerpt:

        #define COMPARE_VALUE 50000 // Valid range is 16-bits 0x0000 (0d) to 0xFFFF (65535d)

        //Start timer in continuous mode sourced by SMCLK
        TIMER_A_configureContinuousMode( TIMER_A1_BASE,
                                         TIMER_A_CLOCKSOURCE_SMCLK,
                                         TIMER_A_CLOCKSOURCE_DIVIDER_16, // Here I changed from "..._1" to "..._16"
                                         TIMER_A_TAIE_INTERRUPT_DISABLE,
                                         TIMER_A_DO_CLEAR
                                         );

        //Initiaze compare mode
        TIMER_A_clearCaptureCompareInterruptFlag(TIMER_A1_BASE,
                                                 TIMER_A_CAPTURECOMPARE_REGISTER_0
                                                 );
        TIMER_A_initCompare(TIMER_A1_BASE,
                            TIMER_A_CAPTURECOMPARE_REGISTER_0,
                            TIMER_A_CAPTURECOMPARE_INTERRUPT_ENABLE,
                            TIMER_A_OUTPUTMODE_OUTBITVALUE,
                            COMPARE_VALUE
                            );

        TIMER_A_startCounter( TIMER_A1_BASE,
                              TIMER_A_CONTINUOUS_MODE
                              );