Clock generating circuit
First Claim
1. A clock generating circuit generating a clock signal comprising:
- an oscillator generating a reference clock signal;
a first latch circuit, provided between first and second nodes, transmitting a level on said first node to said second node when said reference clock signal is at a first logic level and holding a level on said second node in response to transition of said reference clock signal from said first logic level to a second logic level;
a second latch circuit, provided between said second node and an output node for outputting said clock signal, transmitting a level on said second node to said output node when said reference clock signal is at said second logic level and holding a level on said output node in response to transition of said reference clock signal from said second logic level to said first logic level; and
a logic circuit, provided between said output node and said first node, and providing a complementary level of a level on said output node to said first node to generate said clock signal when an activating signal is at a first level, while transmitting a level on said output node to said first node to cease generation of said clock signal when the activating signal is at a second level.
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Accused Products
Abstract
The clock generating circuit includes: an oscillator generating a reference clock signal; an EX-OR gate connected in a ring configuration; and first and second D latch circuits. The EX-OR gate inverts a clock signal to provide the inverted clock signal to the first D latch circuit when an activating signal is at H level. In this case, the clock signal is a clock signal having a clock cycle period of twice that of the reference clock signal. The EX-OR gate provides the clock signal direct to the first D latch circuit when the activating signal is set to L level. In this case, level transition of the clock signal is ceased. Hence, generation of a glitch in the clock signal is prevented from occurring.
10 Citations
13 Claims
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1. A clock generating circuit generating a clock signal comprising:
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an oscillator generating a reference clock signal;
a first latch circuit, provided between first and second nodes, transmitting a level on said first node to said second node when said reference clock signal is at a first logic level and holding a level on said second node in response to transition of said reference clock signal from said first logic level to a second logic level;
a second latch circuit, provided between said second node and an output node for outputting said clock signal, transmitting a level on said second node to said output node when said reference clock signal is at said second logic level and holding a level on said output node in response to transition of said reference clock signal from said second logic level to said first logic level; and
a logic circuit, provided between said output node and said first node, and providing a complementary level of a level on said output node to said first node to generate said clock signal when an activating signal is at a first level, while transmitting a level on said output node to said first node to cease generation of said clock signal when the activating signal is at a second level. - View Dependent Claims (2, 3, 4, 5)
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6. A clock generating circuit generating a clock signal comprising:
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a ring oscillator including an odd number of first inverters connected in a ring configuration, being activated to generate a clock signal when an activating signal is at a first level, while being deactivated to cease generation of said clock signal when said activating signal is at a second level; and
a latch circuit, connected to an output node of said ring oscillator, and holding a level of an output node of said ring oscillator in response to transition of said activating signal from said first level to said second level. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13)
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Specification