Texas Instruments MSP430x1xx - Manual (Page 109)

LFXT1 and XT2 Oscillators
7-9
Basic Clock Module
Figure 7–9. NMI/OSCFault Interrupt Handler
Start of NMI Interrupt Handler
Reset by HW:
OFIE, NMIE, ACCIE
OFIFG = 1 ACCVIFG = 1 NMIFG = 1
No No No
Select DCO For MCLK
SELM.1 = 0
Reset ACCVIFG Reset NMIIFG
User’s Software,
Oscillator Fault
Handler
User’s Software,
Flash Access
Violation Handler
User’s Software,
External NMI
Handler
OFIFG = 0
OFIFG = 0
No
Yes Yes Yes
Reselect Failed
XT Oscillator
Yes
Set NMIE, OFIE,
ACCVIE Within One
Instruction
RETI
End of NMI Int. Handler
Example1:
BIS.B #(NMIIE+OGIE+ACCVIFG), &IE1
Example2:
BIS.B Mask, &IE1 ; Mask Enables Only
; Interrupt Sources
; That are Needed
Optional
Note: Example for MSP430F1xx device