Abstract: A programmable logic device includes a plurality of repeating units, each of which includes interconnecting lines, a logic block comprising logic circuits, and a configuration memory block including a plurality of configuration memory circuits. One of the plurality of repeating units includes: a selection device coupled to output data of the plurality of configuration memory circuits and a shift chain segment input; and a flip flop receiving output of the selection device to output a shift chain segment output.

Abstract: A method and apparatus for connecting a load track (3) of a programmable interconnect to a plurality of intersecting driver tracks (2) of the programmable interconnect. The apparatus comprises a chain of connection cells (9;15), each connection cell being operable to connect the load track of the programmable interconnect to an associated intersecting driver track. Each cell also comprises connection signal receiving means arranged to receive a connection signal and activation signal receiving means arranged to receive an activation signal. The apparatus also comprises connection means arranged to connect the load track of the programmable interconnect to the associated intersecting driver track of the programmable interconnect when the connection signal receiving means has received a connection signal and the activation signal receiving means has received an activation signal.

Abstract: A method and apparatus for connecting a load track (3) of a programmable interconnect to a plurality of intersecting driver tracks (2) of the programmable interconnect. The apparatus comprises a chain of connection cells (9;15), each connection cell being operable to connect the load track of the programmable interconnect to an associated intersecting driver track. Each cell also comprises connection signal receiving means arranged to receive a connection signal and activation signal receiving means arranged to receive an activation signal. The apparatus also comprises connection means arranged to connect the load track of the programmable interconnect to the associated intersecting driver track of the programmable interconnect when the connection signal receiving means has received a connection signal and the activation signal receiving means has received an activation signal.

Abstract: A ring oscillator includes a first logic block having a first input connected to a specific point along a delay path, a first output and a second output, and a second logic block having a first input connected to the first output of the first logic block, a second input connected to the second output of the first logic block, a third input connected to the end of the delay path, and a first output connected to the beginning of the delay path. The first logic block is arranged to alternately switch its first output and second output from logical HIGH to logical LOW, and vice versa, every time a rising edge is input into its first input. The second logic block is arranged to alternately select its first input and its second input every time a rising edge is input into its third input.

Abstract: A ring oscillator comprises a first logic block having a first input connected to a specific point along a delay path, a first output and a second output and a second logic block having a first input connected to the first output of the first logic block, a second input connected to the second output of the first logic block, a third input connected to the end of the delay path and a first output connected to the beginning of the delay path. The first logic block is arranged to, in use, alternately switch its first output and second output from logical HIGH to logical LOW, and vice versa, every time a rising edge is input into its first input. The second logic block is arranged to, in use, alternately select its first input and its second input every time a rising edge is input into its third input.