SWCU194 March 2023 CC1314R10 , CC1354P10 , CC1354R10 , CC2674P10 , CC2674R10
Exception entry occurs when there is a pending exception with sufficient priority and either the processor is in Thread mode, or the new exception is of higher priority than the exception being handled, in which case the new exception preempts the original exception.
When one exception preempts another, the exceptions are nested.
Sufficient priority means that the exception has higher priority than any limits set by the mask registers. An exception with lower priority than this is pending but is not handled by the processor.
When the processor takes an exception, unless the exception is a tail-chained or a late-arriving exception, the processor pushes information onto the current stack. This operation is referred to as stacking and the structure of the data stacked is referred as the stack frame.
The Cortex‑M33 processor can automatically stack the architected floating-point state on exception entry.