Data gating using scan enable pin
AssigneeApple Inc.
InventorsFNU Rajeev Kumar, Chandan Shantharaj
Life of this patent
Estimating the term…
Abstract
An Integrated Circuit (IC) includes a storage element and control circuitry. The control circuitry is configured to select, responsively to a scan-enable control, between a functional-data input and a scan-data input to serve as an input to the storage element, to selectively disable toggling of an output of the storage element, responsively to a clock-enable control, by gating a clock signal provided to the storage element, and, while the clock-enable control indicates that the output of the storage element is to be disabled from toggling, to select the input of the storage element to be the scan-data input.
Claims20
An Integrated Circuit (IC), comprising:
- a storage element;
- and
- control circuitry, configured to:
- responsively to a scan-enable control, select between a functional-data input and a scan-data input to serve as an input to the storage element;
- responsively to a clock-enable control, selectively disable toggling of an output of the storage element by gating a clock signal provided to the storage element;
- and
- while the clock-enable control indicates that the output of the storage element is to be disabled from toggling, select the input of the storage element to be the scan-data input.
A method in an Integrated Circuit (IC) that includes at least a storage element, the method comprising:
- responsively to a scan-enable control, selecting between a functional-data input and a scan-data input to serve as an input to the storage element;
- responsively to a clock-enable control, selectively disabling toggling of an output of the storage element by gating a clock signal provided to the storage element;
- and
- while the clock-enable control indicates that the output of the storage element is to be disabled from toggling, selecting the input of the storage element to be the scan-data input.
An apparatus comprising a processor that comprises (i) fetch circuitry configured to fetch instructions and (ii) execute circuitry configured to execute instructions, wherein one or both of the fetch circuitry and the execute circuitry comprise:
- a storage element;
- and
- control circuitry, configured to:
- responsively to a scan-enable control, select between a functional-data input and a scan-data input to serve as an input to the storage element;
- responsively to a clock-enable control, selectively disable toggling of an output of the storage element by gating a clock signal provided to the storage element;
- and
- while the clock-enable control indicates that the output of the storage element is to be disabled from toggling, select the input of the storage element to be the scan-data input.
Dependencies are inferred from the claim text.