As soon as the analog comparator settings change, the output is invalid for a duration depending on ISEL current.
A masking period is automatically triggered as soon as a write access is performed on the ACC_MR or ACC Analog Control Register (ACC_ACR) (regardless of the register data content).
When ISEL = 0, the mask period is 8 × tperipheral clock.
When ISEL = 1, the mask period is 128 × tperipheral clock.
The masking period is reported by reading a negative value (bit 31 set) on the ACC Interrupt Status Register (ACC_ISR).