The header file <in430.h> defines a number of intrinsic functions
of general use for the MSP430 processor.
Status register manipulation
_BIC_SR, _BIC_SR_IRQ,
_BIS_SR, _BIS_SR_IRQ,
_DINT, _EINT
Byte order swapping
_LSWPB, _LSWPW,
_SWPB
Miscellaneous functions
_NOP, _OPC