Sticky bits keep their value when they changed to logical 1 as long until the status-register is read by the CPU. This is very important when the sticky bit is generating an interrupt, it has to be cleared within the isr. Otherwise the interrupt handling will not function properly.
In this mode, the status register inputs are sampled on each cycle of the status and control clock. If the signal is high in a given sample, it is captured in the status bit and remains high, regardless of the subsequent state of the input. When the CPU or DMA reads the status register the bit is cleared. The status register clearing is independent of mode and occurs even if the UDB clock is disabled; it is based on the bus clock and occurs as part of the read operation.