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Set
Reset
Q
Set
Reset
Q
Set
Q
Q
Set
Reset
PUC
NMI _ IRQA
OFIFG
OFIE
NMIRS
Set
Reset
Q
Set
Reset
Q
XT1OFFG
XT2OFFG
XT1_OF
XT2_OF
POR
XT2_OscFault
OscFault_Clr
OscFault_Set
Q
Q
XT1_HF_OscFault
XT1_LF_OscFault
Clock System Operation
Figure 3-3. Oscillator Fault Logic
NOTE:
Fault conditions
XT1_LF_OscFault:
This signal is set after the XT1 (LF mode) oscillator has stopped
operation and is cleared after operation resumes. The fault condition causes XT1OFFG to be
set and remain set. If the user clears XT1OFFG and the fault condition still exists, XT1OFFG
remains set.
XT1_HF_OscFault:
This signal is set after the XT1 (HF mode) oscillator has stopped
operation and is cleared after operation resumes. The fault condition causes XT1OFFG to be
set and remain set. If the user clears XT1OFFG and the fault condition still exists, XT1OFFG
remains set.
XT2_OscFault:
This signal is set after the XT2 oscillator has stopped operation and is
cleared after operation resumes. The fault condition causes XT2OFFG to be set and remain
set. If the user clears XT2OFFG and the fault condition still exists, XT2OFFG remains set.
NOTE:
Fault logic
As long as a fault condition still exists, the OFIFG remains set. The application must take
special care when clearing the OFIFG signal. If no fault condition remains when the OFIFG
signal is cleared, the clock logic switches back to the original user settings prior to the fault
condition.
77
SLAU272C – May 2011 – Revised November 2013
Clock System (CS)
Copyright © 2011–2013, Texas Instruments Incorporated