Power supply voltage adjusting device
AssigneeFujitsu Limited
InventorsHiroshi Okano, Atsuki Inoue
Life of this patent
Estimating the term…
Abstract
In a semiconductor integrated circuit including plural types of transistors having different threshold voltages, a plurality of oscillators including respective types of transistors are provided. The respective oscillation frequencies of these oscillators are counted, and based on the count values, a voltage to be set on a power supply voltage device for the semiconductor integrated circuit is determined according to the count values.
Claims10
A power supply voltage adjusting device which adjusts a power supply voltage of a semiconductor integrated circuit configured by plural types of transistors having different threshold voltages, comprising:
- a first ring oscillator to oscillate a first oscillation signal, all of transistors included in the first ring oscillator, which are provided in a ring path of the first ring oscillator and are used for oscillating the first oscillation signal, having a high threshold value;
- a second ring oscillator to oscillate a second oscillation signal, all of transistors included in the second ring oscillator, which are provided in a ring path of the second ring oscillator and are used for oscillating the second oscillation signal, having a low threshold value;
- a first counter to count first oscillation frequency of the first oscillation signal to output a first count value and to count second oscillation frequency of the second oscillation signal to output a second count value;
- a converter to convert the first count value into a first power supply voltage corresponding to the high threshold value and the second count value into a second power supply voltage corresponding to the low threshold value;
- and
- a controller to output a control signal indicating one of the first power supply voltage and the second power supply voltage.
A power supply voltage adjusting device which adjusts a power supply voltage of a semiconductor integrated circuit configured by plural types of transistors having different threshold voltages, comprising:
- a first ring oscillator to oscillate a first oscillation signal, all of transistors included in the first ring oscillator, which are provided in a ring path of the first ring oscillator and are used for oscillating the first oscillation signal, having a high threshold value;
- a second ring oscillator to oscillate a second oscillation signal, all of transistors included in the second ring oscillator, which are provided in a ring path of the second ring oscillator and are used for oscillating the second oscillation signal, having a low threshold value;
- a first counter to count first oscillation frequency of the first oscillation signal to output a first count value and to count second oscillation frequency of the second oscillation signal to output a second count value;
- a converter to convert the first count value into a first power supply voltage corresponding to the high threshold value and the second count value into a second power supply voltage corresponding to the low threshold value;
- and
- a controller to output a control signal indicating one of the first power supply voltage and the second power supply voltage,
- wherein a power supply device for providing a power supply for the semiconductor integrated circuit sets a power supply voltage depending on the output control signal.
A power supply voltage adjusting device which adjusts a power supply voltage of a semiconductor integrated circuit configured by plural types of transistors having different threshold voltages, comprising:
- a first ring oscillator to oscillate a first oscillation signal, all of transistors included in the first ring oscillator, which are provided in a ring path of the first ring oscillator and are used for oscillating the first oscillation signal, having a high threshold value;
- a second ring oscillator to oscillate a second oscillation signal, all of transistors included in the second ring oscillator, which are provided in a ring path of the second ring oscillator and are used for oscillating the second oscillation signal, having a low threshold value;
- a first counter to count first oscillation frequency of the first oscillation signal to output a first count value and to count second oscillation frequency of the second oscillation signal to output a second count value;
- a memory element to hold power supply voltage information determined depending on the first count value and the second count value;
- and
- a controller to read the power supply voltage information from the memory element and outputting a control signal indicating the read power supply voltage information.
Dependencies are inferred from the claim text.