Abstract: Primary and secondary apparatuses avoid concurrent performance of activities, wherein the secondary apparatus has a best and possibly different worst case minimum amounts of time required to perform activity. The primary apparatus ascertains a first future moment when it will become inactive and ascertains whether its upcoming period of inactivity will not be less than the secondary apparatus' best case minimum amount of time required to perform activity. If not, the primary apparatus asserts, in advance of the first future moment, an inactivity indicator signal indicating its upcoming inactivity. The interval between assertion of the inactivity indicator signal and the first future moment is greater than or equal to a difference between the secondary apparatus' worst and best case minimum amounts of time required to perform activity.

Abstract: Primary and secondary apparatuses avoid concurrent performance of activities, wherein the secondary apparatus has a best and possibly different worst case minimum amounts of time required to perform activity. The primary apparatus ascertains a first future moment when it will become inactive and ascertains whether its upcoming period of inactivity will not be less than the secondary apparatus' best case minimum amount of time required to perform activity. If not, the primary apparatus asserts, in advance of the first future moment, an inactivity indicator signal indicating its upcoming inactivity. The interval between assertion of the inactivity indicator signal and the first future moment is greater than or equal to a difference between the secondary apparatus' worst and best case minimum amounts of time required to perform activity.

Abstract: An adaptive equalizer includes a digital linear filter having adjustable weighting factors and which is connected to a summator and a control unit so as to form two filter loops, one direct and the other recursive, the filter being shared in both loops. The control unit provides a weighting factor which establishes a selected relative proportioning of the data signals which traverse each loop, so that the equalizer is proportioned as to the degree to which it provides direct filtering and the degree to which it provides recursive filtering. Recursive filtering is employed to the maximum extent consistent with operating stability, the relative proportion of direct filtering being increased as necessary in order to maintain stability during equalization of any particular received data signal.