Texas Instruments MSP430x1xx Computer Hardware User Manual


 
System Reset and Initialization
2-5
System Resets, Interrupts, and Operating Modes
2.1.3 Device Initial Conditions After System Reset
After a POR, the initial MSP430 conditions are:
- The RST/NMI pin is configured in the reset mode.
- I/O pins are switched to input mode as described in the Digital I/O chapter.
- Other peripheral modules and registers are initialized as described in their
respective chapters in this manual.
- Status register (SR) is reset.
- The watchdog timer powers up active in watchdog mode.
- Program counter (PC) is loaded with address contained at reset vector
location (0FFFEh). CPU execution begins at that address.
Software Initialization
After a system reset, user software must initialize the MSP430 for the
application requirements. The following must occur:
- Initialize the SP, typically to the top of RAM.
- Initialize the watchdog to the requirements of the application.
- Configure peripheral modules to the requirements of the application.
Additionally, the watchdog timer, oscillator fault, and flash memory flags can
be evaluated to determine the source of the reset.