SPRUII0F May 2019 – June 2024 TMS320F28384D , TMS320F28384D-Q1 , TMS320F28384S , TMS320F28384S-Q1 , TMS320F28386D , TMS320F28386D-Q1 , TMS320F28386S , TMS320F28386S-Q1 , TMS320F28388D , TMS320F28388S
The CM supports both level-sensitive and pulse interrupts. Pulse interrupts are also described as edge-triggered interrupts.
A level-sensitive interrupt is held asserted until the peripheral deasserts the interrupt signal. Typically this happens because the ISR accesses the peripheral, causing it to clear the interrupt request. A pulse interrupt is an interrupt signal sampled synchronously on the rising edge of the CM clock. To ensure the NVIC detects the interrupt, the peripheral must assert the interrupt signal for at least one clock cycle, during which the NVIC detects the pulse and latches the interrupt.
When the CM enters the ISR, it automatically removes the pending state from the interrupt (see Section 41.7.2 for more information). For a level-sensitive interrupt, if the signal is not deasserted before the CM returns from the ISR, the interrupt becomes pending again, and the CM must execute its ISR again. As a result, the peripheral can hold the interrupt signal asserted until it no longer needs servicing.