Power control circuitry, circuitry for analysing a switched power rail, and method of controlling connection of a power source to a switched power rail
First Claim
1. Power control circuitry for controlling connection of a power source having a source voltage level to a switched power rail used to provide power to an associated circuit block, the power control circuitry comprising:
- a switch block for selectively connecting the switched power rail to the power source;
a switch controller for controlling operation of the switch block;
ring oscillator circuitry powered from the switched power rail and producing an oscillating output signal; and
analysis circuitry for analysing change in frequency of the oscillating output signal produced by the ring oscillator circuitry during a period of time when the switched power rail is not at the source voltage level, and to cause the switch controller to control at least one aspect of the operation of the switch block in dependence on said analysis.
1 Assignment
0 Petitions
Accused Products
Abstract
Power control circuitry is provided for controlling connection of a power source having a source voltage level to a switched power rail to provide power to an associated circuit block. The power control circuitry comprises a switch block for selectively connecting the switched power rail to the power source, and a switch controller for controlling operation of the switch block. A ring oscillator circuit is powered from the switched power rail and produces an oscillating output signal, and analysis circuitry is then used to analyse change in frequency of the oscillating output signal produced by the ring oscillator circuit during a period of time when the switched power rail is not at the source voltage level. The switch controller is then arranged to control at least one aspect of the operation of the switch block in dependence on the analysis. This technique provides a simple and effective digital technique for observing voltage changes on the switched power rail.
36 Citations
22 Claims
-
1. Power control circuitry for controlling connection of a power source having a source voltage level to a switched power rail used to provide power to an associated circuit block, the power control circuitry comprising:
-
a switch block for selectively connecting the switched power rail to the power source; a switch controller for controlling operation of the switch block; ring oscillator circuitry powered from the switched power rail and producing an oscillating output signal; and analysis circuitry for analysing change in frequency of the oscillating output signal produced by the ring oscillator circuitry during a period of time when the switched power rail is not at the source voltage level, and to cause the switch controller to control at least one aspect of the operation of the switch block in dependence on said analysis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
-
-
20. Circuitry for analysing a switched power rail used to provide power to an associated circuit block, the switched power rail being connectable to a power source having a source voltage level, the circuitry comprising:
-
a switch block for selectively connecting the switched power rail to the power source; a switch controller for controlling operation of the switch block; ring oscillator circuitry powered from the switched power rail and producing an oscillating output signal; and analysis circuitry for analysing change in frequency of the oscillating output signal produced by the ring oscillator circuitry during a period of time when the switched power rail is not at the source voltage level in order to produce information characterising at least one analogue voltage property of the switched power rail.
-
-
21. A method of controlling connection of a power source having a source voltage level to a switched power rail used to provide power to an associated circuit block, the method comprising the steps of:
-
selectively connecting the switched power rail to the power source via a switch block; operating ring oscillator circuitry from the switched power rail in order to produce an oscillating output signal; analysing change in frequency of the oscillating output signal produced by the ring oscillator circuitry during a period of time when the switched power rail is not at the source voltage level; and controlling at least one aspect of the operation of the switch block in dependence on said analysis.
-
-
22. Power control logic for controlling connection of a power source means having a source voltage level to a switched power rail means used to provide power to an associated circuit block means, the power control logic comprising:
-
a switch block means for selectively connecting the switched power rail means to the power source means; a switch controller means for controlling operation of the switch block means; ring oscillator means powered from the switched power rail means for producing an oscillating output signal; and analysis means for analysing change in frequency of the oscillating output signal produced by the ring oscillator means during a period of time when the switched power rail means is not at the source voltage level, and to cause the switch controller means to control at least one aspect of the operation of the switch block means in dependence on said analysis.
-
Specification