High Frequency Digital Oscillator-on-Demand with Synchronization
First Claim
1. A method to produce a digital on-demand digital oscillator of high frequency and to derive lower frequency clocks by digital division, and having the ability to start and stop oscillating, almost instantaneously, and remaining synchronized to an external clock, the method comprising the steps of:
- a) incorporating a base oscillator comprising a feedback loop, wherein the feedback loop comprises both a bulk delay and a fine delay, and wherein said base oscillator is designed to oscillate at a nominal frequency fn which is 2n times that of the external clock fclk, with n being a integer;
b) calculating the number nb of periods of the base oscillator which are equal or less than the period nclk of the external clock;
c) setting the bulk delay delta B equal to nb*pn, where pn=1/fn;
d) setting the fine delay delta F equal to pclk−
delta B where pclk=1/fclk,so that after including the bulk and fine delays in the feedback loop the base oscillator will have a frequency of 2n times the external clock,and the method further comprising the steps of;
e) gating the on-demand oscillator to an “
ON”
state in synchronization with the external clock, in order to begin oscillating,wherein steps b) through e) are performed within one period of the external clock, and wherein phase locked loops are not used in the on-demand oscillator.
1 Assignment
0 Petitions
Accused Products
Abstract
A High Frequency Digital Oscillator contains a ring oscillator having an output fn, and having coarse and fine frequency adjustments, wherein the input signal f1 is the input to both the ring oscillator and the High-Frequency Digital Oscillator, which has a multiplicity of output signals including f2, f4, and f8 at one-half, one fourth, and one-eighth the frequency of fn respectively, and wherein an input gating signal causes the oscillator to start or stop, a signal fc=¼*(f4) causing a coarse frequency adjustment and a signal Δ=(1/f1−1/fc) making a fine adjustment, and by stopping the new output before the rising edge of f1; and then restarting starting the new output at the rising edge of so that the output and input are synchronized.
-
Citations
18 Claims
-
1. A method to produce a digital on-demand digital oscillator of high frequency and to derive lower frequency clocks by digital division, and having the ability to start and stop oscillating, almost instantaneously, and remaining synchronized to an external clock, the method comprising the steps of:
-
a) incorporating a base oscillator comprising a feedback loop, wherein the feedback loop comprises both a bulk delay and a fine delay, and wherein said base oscillator is designed to oscillate at a nominal frequency fn which is 2n times that of the external clock fclk, with n being a integer; b) calculating the number nb of periods of the base oscillator which are equal or less than the period nclk of the external clock; c) setting the bulk delay delta B equal to nb*pn, where pn=1/fn; d) setting the fine delay delta F equal to pclk−
delta B where pclk=1/fclk,so that after including the bulk and fine delays in the feedback loop the base oscillator will have a frequency of 2n times the external clock, and the method further comprising the steps of; e) gating the on-demand oscillator to an “
ON”
state in synchronization with the external clock, in order to begin oscillating,wherein steps b) through e) are performed within one period of the external clock, and wherein phase locked loops are not used in the on-demand oscillator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. An electronic digital on-demand digital oscillator system of high frequency which produces lower frequency clocks by digital division, and which has the ability to start and stop oscillating, almost instantaneously, while remaining synchronized to an external clock, said system comprising:
-
a) a base oscillator comprising a feedback loop, wherein the feedback loop comprises both a bulk delay and a fine delay, and wherein said base oscillator is designed to oscillate at a nominal frequency fn which is 2n times that of the external clock fclk, with n being a integer; b) means for calculating the number nb of periods of the base oscillator which are equal of less than the period nclk of the external clock; c) means for setting the bulk delay delta B equal to nb*pn, where pn=1/fn; d) means for setting the fine delay delta F equal to pclk−
delta B where pclk=1/fclk,so that after including the bulk and fine delays in the feedback loop the base oscillator will have a frequency of 2n times the external clock, and the system further comprising; e) gating means to set the on-demand oscillator to an “
ON”
state in synchronization with the external clock, on to begin oscillating,wherein phase locked loops are not used in the on-demand oscillator system. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
-
Specification