Skewed latch flip-flop with embedded scan function
AssigneeSun Microsystems, Inc.
InventorRitesh Saraf
Life of this patent
Estimating the term…
Abstract
A flip-flop circuit with embedded scan capabilities uses a skewed latch to pull one end of the flip-flop either up or down while another end of the flip-flop is active. Further, the flip-flop is designed such that a data node and a scan node are coupled to a master stage, which contains the skewed latch. The data node and scan node values are initially generated from different ends of the flip-flop. Based upon clock dependencies and whether the flip-flop is in a normal mode or a scan mode, the master stage passes a value to a slave stage dependent upon the data node and scan node values. Thereafter, the slave stage outputs a result based on the value passed from the master stage.
Claims18
A flip-flop circuit with embedded scan capabilities and having a master stage and a slave stage, comprising:
- a data input control stage that selectively controls a value on a data node that is coupled to the master stage and the slave stage;
- and
- a scan input control stage that selectively controls a value on a scan node that is coupled to the master stage.
A method for performing operations using a flip-flop with embedded scan capabilities and having a master stage and a slave stage, comprising:
- selectively controlling a value on a data node dependent upon a data input control stage and a clock input control stage, wherein the data node is coupled to the master stage and the slave stage;
- selectively controlling a value on a scan node dependent upon a scan input control stage and the clock input control stage, wherein the scan node is coupled to the master stage;
- selectively controlling the slave stage dependent upon the master stage and the clock input control stage;
- and
- selectively generating an output of the flip-flop dependent upon the slave stage.
Dependencies are inferred from the claim text.