The NVIC_ISPR forces interrupts into the pending state, and shows which interrupts are pending.
SETPEND | Interrupt set-pending bits. Write: 0 = No effect. 1 = Changes interrupt state to pending. Read: 0 = Interrupt is not pending. 1 = Interrupt is pending. Note: Writing 1 to the NVIC_ISPR bit corresponding to: An interrupt that is pending has no effect. A disabled interrupt sets the state of that interrupt to pending. |