should be set to one half the alarm notification time in order to meet the alarm notification time objective the error detection and time base control registers should be set as shown in table 2 the last row of table 2 assumes that tbh is set to 1 i e the time base is 500 u03bcs and a0440 20 if the ber is higher than the programmed threshold notification will take place within the amount of time listed for the threshold that matches the incoming ber for example if the threshold is programmed to monitor for ber at a level of 1 0e 5 notification in 16 ms or less but the actual incoming ber is 1 0e 3 then the notification interrupt will be set to 1 ms rather than waiting until the end of the 16 ms window 0026 fig3 illustrates the methods of the invention as a state machine having four states and ten triggers the states are labeled the idle alarm state 10 the alarm set state 12 the burst alarm clear state 14 and the burst alarm set state 16 the triggers are labelled a j and are defined in terms of whether or not burst mode is enabled a comparison of ec with the detection and recovery thresholds and a comparison of fc with detection and recovery time base thresholds as mentioned above the operation of the invention is significantly affected by whether or not the burst bit is set to indicate operation in the burst mode when the burst mode is turned off the method of the invention is to proceed from an idle.