Abstract: A method and apparatus for fault testing a clock distribution network for A.C. and D.C. faults. The fault testing apparatus includes test latch circuit means and is adapted to initially test for D.C. (stuck) faults and to thereafter continuously monitor a plurality of clock signal lines to detect A.C. clock faults.

Abstract: In a data processing system in which data is sent over a data path between at least first and second devices, a clock distribution network is provided with the capability of selectively delaying the clock signal to either the sending or receiving devices to stress the short and long data paths.

Abstract: A method and apparatus for fault testing a clock distribution network which provides a plurality of clock signal lines to the logic networks which comprise a data processor. The fault testing apparatus includes a decoder for selecting one of the clock signal lines to be tested, and a test latch which is clocked by the selected clock signal line. The selected clock signal line is tested by setting the test latch to a first logic value (e.g., binary ZERO) and maintaining a second logic value (e.g., binary ONE) at the test latch input. If the second logic value is stored in the test latch when the clock distribution network is inhibited, then a stuck-on fault is indicated for the selected clock signal line. If the second logic value fails to be stored in the test latch when the clock distribution network is enabled, then a stuck-off fault is indicated for the selected clock signal line. Each clock signal line in the clock distribution network may be tested in this manner.