msp430fr413x_WDT_05.c

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 *                       MSP430 CODE EXAMPLE DISCLAIMER
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 * MSP430 code examples are self-contained low-level programs that typically
 * demonstrate a single peripheral function or device feature in a highly
 * concise manner. For this the code may rely on the device's power-on default
 * register values and settings such as the clock configuration and care must
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//******************************************************************************
//  MSP430FR413x Demo - WDT,  Reset on Invalid Address fetch, Toggle P1.0
//
//  Description: This program demonstrates how a reset is executed if the CPU
//  tries to fetch instructions from within the module register memory address
//  range (0x0100 --0x0FEF) or from within unused address ranges. Toggle P1.0
//  by xor'ing P1.0 inside of a software loop that ends with TAR loaded with
//  3FFFh - op-code for "jmp $". This simulates a code error. The MSP430
//  will force a reset because it will not allow a fetch from within the address
//  range of the peripheral memory, as is seen by return to the mainloop and
//  LED flash.
//  ACLK = REFO = 32kHz, MCLK = SMCLK = default DCO ~1MHz.
//
//                MSP430FR4133
//             -----------------
//         /|\|                 |
//          | |                 |
//          --|RST              |
//            |                 |
//            |             P1.0|-->LED
//
//  Wei Zhao
//  Texas Instruments Inc.
//  Jan 2014
//  Built with IAR Embedded Workbench v5.60 & Code Composer Studio v5.5
//******************************************************************************
#include <msp430.h>

int main(void)
{
    WDTCTL = WDTPW | WDTHOLD;               // Stop watchdog timer

    P1DIR |= BIT0;                          // Set P1.0 to output direction

    // Disable the GPIO power-on default high-impedance mode
    // to activate previously configured port settings
    PM5CTL0 &= ~LOCKLPM5;

    TA0R = 0x3FFF;                          // Valid opcode (for "jmp $")

    while(1)
    {
        P1OUT ^= BIT0;                      // Toggle P1.0 using exclusive-OR
        __delay_cycles(50000);              // Delay
        ((void (*)())0x170)();              // Invalid fetch ("call #0170h")
        __no_operation();                   // ** Should never get here **
    }
}