Miscellaneous active electrical nonlinear devices – circuits – and – Signal converting – shaping – or generating – Clock or pulse waveform generating
Reexamination Certificate
2007-11-14
2009-12-01
Cox, Cassandra (Department: 2816)
Miscellaneous active electrical nonlinear devices, circuits, and
Signal converting, shaping, or generating
Clock or pulse waveform generating
C327S047000
Reexamination Certificate
active
07626436
ABSTRACT:
An Automatic System Clock Detection System (ASCDS) may provide integrated circuits (ICs) with the capability to detect the frequency of an external crystal oscillator or clock source, and adjust the IC's internal PLL accordingly for proper IC operation. The frequency detection and PLL adjustment may be performed without any additional pins on the IC, and/or without requiring any additional external information. The ASCDS may be configured with an internal ring oscillator, which may be generated from standard logic elements, a watchdog counter, and an input clock counter. When the IC comes out of power on reset (POR), the ASCDS may compare the input clock counter with the watchdog counter, and determine the clock frequency of the input clock. It may then set the PLL parameters to ensure correct IC operation.
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Bohm Mark R.
Li Shawn Shaojie
Nigam Akhlesh
Pennell Michael J.
Cox Cassandra
Hood Jeffrey C.
Meyertons Hood Kivlin Kowert & Goetzel P.C.
Standard Microsystems Corporation
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