Digital clock controller, radio receiver, and methods for use therewith

• US 7,620,131 B2
• Filed: 11/22/2005
• Issued: 11/17/2009
• Est. Priority Date: 11/22/2005
• Status: Expired due to Fees

• Current Assignee: North Star Innovations Inc. (Wi-LAN Inc.)
• Original Assignee: SigmaTel Incorporated (NXP Semiconductors NV)
• Inventors: May, Michael R., Lowe, Erich
• Primary Examiner(s): Wang, Ted M
• Application Number:
  US11/287,549
• Publication Number:
  US 20070165747A1
• Time in Patent Office: 1,456 Days
• Field of Search: 375/316, 375/349, 375/354, 341/117, 341/110, 327/144
• US Class Current: 375/349
• CPC Class Codes: H04B 15/02 Reducing interference from electric apparatus by means located at or near the interfering apparatus
• CPC Class Codes: H04B 2215/064 Reduction of clock or synthesizer reference frequency harmonics

Abstract

A digital clock generator includes a base clock generator for generating a base clock signal at a variable base clock frequency in response to a control signal. A digital clock controller generates a digital clock signal having a substantially constant number of digital clock cycles over a predetermined period.

Claims

1. A radio receivers comprising:

an analog front end to receive a radio signal containing a selected one of a plurality of channel signals, and to convert the selected one of the plurality of channel signals into a digital signal;

a digital clock generator to generate a base clock signal at a base clock frequency that varies based on the selected one of the plurality of channel signals and to generate a digital clock signal having a substantially constant number of digital clock cycles over a predetermined period, wherein the digital clock generator includes a stall cycle module to produce a stall signal in response to a first value of a control signal, and wherein the digital clock generator generates the digital clock signal by;

inserting a plurality of stall cycles in a preliminary clock signal over the predetermined period at a second value of the control signal; and

inserting no stall cycles in the preliminary clock signal over the predetermined period at a third value of the control signal; and

a digital section, operably coupled to the analog front end and the digital clock generator, to convert the digital signal into at least one audio signal that corresponds to the selected one of the plurality of channel signals, the digital section having a first digital module that operates based on the base clock signal and a second digital module that operates based on the digital clock signal.

2. The radio receiver of claim 1, wherein the digital clock generator further includes:

a delay module to produce the digital clock signal by inserting a delay in the preliminary clock signal having a duration of one stall cycle.

3. The radio receiver of claim 1, wherein the digital clock generator further includes:

a preliminary clock cycle generator to produce the preliminary clock signal.

4. The radio receiver of claim 1, wherein the digital clock generator spreads the substantially constant number of digital clock cycles substantially uniformly over the predetermined period.

5. The radio receiver of claim 1, wherein the received radio signal is one of:

a broadcast frequency modulated radio signal, a broadcast amplitude modulated radio signal, a broadcast satellite radio signal, an in-band on-channel digital radio signal, a Bluetooth radio signal, and a broadcast cable signal.

6. The radio receiver of claim 1, wherein at least one of the analog front end, the digital clock generator, and the digital section, are implemented as part of a system on a chip integrated circuit.

7. The radio receiver of claim 1., wherein the base clock frequency is less than a carrier frequency of the selected one of the plurality of channel signals, and wherein the base clock frequency and integer multiples of the base clock frequency are not substantially equal to the carrier frequency of the selected one of the plurality of channel signals.

8. The radio receiver of claim 1, wherein the analog front end includes an in-phase signal path and a quadrature-phase signal path.

9. The radio receiver of claim 1, further comprising:

a channel selector, to generate a control signal that corresponds to a selected one of the plurality of channel signals in the received radio signal having a corresponding carrier frequency; and

a local oscillator, operably coupled to the analog front end and a reference oscillation, for generating a local oscillation signal based on the control signal.

10. A digital clock generator comprising:

a base clock generator to generate a base clock signal at a variable base clock frequency in response to a control signal; and

a digital clock controller to generate a digital clock signal having a substantially constant number of digital clock cycles over a predetermined period wherein the digital clock controller includes a stall cycle module for producing a stall signal in response to a first value of the control signal, and wherein the digital clock controller is to insert a plurality of stall cycles in a preliminary clock signal over the predetermined period at a second value of the control signal, and to insert no stall cycles in the preliminary clock signal over the predetermined period at a third value of the control signal.

11. The digital clock generator of claim 10, wherein the digital clock controller further includes:

a delay module to produce the digital clock signal by inserting a delay in the preliminary clock signal having a duration of one stall cycle.

12. The digital clock generator of claim 10, wherein the digital clock controller further includes:

a preliminary clock cycle generator to produce the preliminary clock signal.

13. A method, comprising:

generating a base clock signal at a variable base clock frequency at a base clock generator in response to a control signal; and

generating a digital clock signal having a substantially constant number of digital clock cycles over a predetermined period at a digital clock controller, wherein generating the digital clock signal includes producing a stall signal at a first value of the control signal, inserting a plurality of stall cycles in a preliminary clock signal over the predetermined period at a second value of the control signal, and inserting no stall cycles in the preliminary clock signal over the predetermined period at a third value of the control signal.

14. The method of claim 13, wherein generating the digital clock signal includes inserting a delay in the preliminary clock signal having a duration of one stall cycle when the stall signal is produced.