Miscellaneous active electrical nonlinear devices – circuits – and – Signal converting – shaping – or generating – Clock or pulse waveform generating
Patent
1997-01-17
1999-02-23
Wambach, Margaret Rose
Miscellaneous active electrical nonlinear devices, circuits, and
Signal converting, shaping, or generating
Clock or pulse waveform generating
327146, 327150, 327151, 327159, 327160, 327241, 327244, H03K 104
Patent
active
058748466
ABSTRACT:
A system is provided for generating an accurate and stable output clock signal of a desired output frequency in response to a system clock signal having a system clock period. The system uses an accurate and stable reference clock signal. The system comprises a measuring circuit and a ratio counter. The measuring circuit receives and processes the system clock signal and produces a measurement, referred to as the system clock measurement, that is indicative of the system clock period. The ratio counter receives the system clock signal and the system clock measurement and generates the output clock signal. The system is resistant to noise in the output clock signal caused by asynchronicity between the system clock signal and the reference clock signal. The system is resistant because it employs at least one of a lock-on unit and a synchronizing controller in operating the clock measuring circuit. The lock-on unit suppresses updating of the system clock measurement if a new measurement differs from the old measurement by no more than a window size. The synchronizing controller assures correct synchronization in the clock measuring circuit despite the asynchronicity of the system clock signal and the reference clock signal by enabling counters within the measuring circuit within a time window of each other.
REFERENCES:
patent: 4982110 (1991-01-01), Yokogawa et al.
patent: 4985754 (1991-01-01), Levan
patent: 5068717 (1991-11-01), Jenison
patent: 5103466 (1992-04-01), Bazes
patent: 5206726 (1993-04-01), Okuda
patent: 5307156 (1994-04-01), Yamamoto et al.
patent: 5455628 (1995-10-01), Bishop
patent: 5526055 (1996-06-01), Zhang et al.
patent: 5663688 (1997-09-01), Delmas et al.
patent: 5705945 (1998-01-01), Wee
"CH7001 VGA to NTSC/PAL Encoder," Rev. 1.4, Product Literature, Chrontel, Inc., Mar. 26, 1996, pp. 1-20.
Nillesen, "Line-Locked Digital Colour Decoding," Phillips Semiconductors, Jun. 1991, pp. 33-39.
Chrontel Incorporated
Wambach Margaret Rose
LandOfFree
Method and apparatus for frequency generation in a synchronous s does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for frequency generation in a synchronous s, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for frequency generation in a synchronous s will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-310470