Analog Devices VISUALDSP++ 3.5 Manual page 320

C Run-Time Library Reference
interrupt(SIG_PWRDWN, SIG_IGN);
/* enable power down interrupt and register ISR */
interruptf(SIG_PWRDWN, handler);
/* disable power down interrupt */
interruptf(SIG_PWRDWN, SIG_IGN);
}
See Also
signal, raise
3-66 VisualDSP++ 3.5 C/C++ Compiler and Library Manual
for ADSP-219x DSPs