Clock masking scheme in a mixed-signal system

• US 8,594,170 B2
• Filed: 10/24/2011
• Issued: 11/26/2013
• Est. Priority Date: 10/24/2011
• Status: Expired due to Fees

• Current Assignee: Sigear Europe Sarl
• Original Assignee: Sigear Europe Sarl
• Inventors: Mombers, Friederich, Porret, Alain-Serge, Thierry, Melly
• Primary Examiner(s): Puente, Eva
• Application Number:
  US13/280,308
• Publication Number:
  US 20130101006A1
• Time in Patent Office: 764 Days
• Field of Search: 375/226, 375/316, 375/354, 327/298, 327/297
• US Class Current: 375/226
• CPC Class Codes: G06F 1/10 Distribution of clock signals , e.g. skew
• CPC Class Codes: H04L 2027/0048 Frequency multiplication
• CPC Class Codes: H04L 27/0014 Carrier regulation of chaotic carriers H04L27/001; for multicarrier receivers H04L27/2657

Abstract

A method in a mixed-signal system to prevent overlapping of clock edges of one or more digital clock signals and clock edges of one or more analog clock signals where the digital clock signals and the analog clock signals are digitally controlled includes generating one or more timing window pulses that are centered around the clock edges of one of the digital clock signals or the analog clock signals; combining the timing window pulses to generate a gating signal, the gating signal having an active logical level at each of the timing window pulses; and applying the gating signal to gate or delay clock edges of the other one of the digital clock signals or the analog clock signals.

Claims

1. A method in a mixed-signal system to prevent overlapping of clock edges of one or more digital clock signals and clock edges of one or more analog clock signals, the digital clock signals and the analog clock signals being digitally controlled, the method comprising:

generating one or more timing window pulses that are centered around the clock edges of one of the digital clock signals or the analog clock signals;

combining the timing window pulses to generate a gating signal, the gating signal having an active logical level at each of the timing window pulses; and

applying the gating signal to gate or delay clock edges of the other one of the digital clock signals or the analog clock signals.

2. The method of claim 1, wherein generating one or more timing window pulses comprises generating one or more timing window pulses that are centered around the clock edges of the analog clock signals;

and applying the gating signal to gate or delay clock edges comprises applying the gating signal to gate or delay clock edges of the digital clock signals using the gating signal.

3. The method of claim 1, wherein generating one or more timing window pulses comprises generating one or more timing window pulses that are centered around the clock edges of the digital clock signals;

and applying the gating signal to gate or delay clock edges comprises applying the gating signal to gate or delay clock edges of the analog clock signals using the gating signal.

4. The method of claim 1, wherein the mixed-signal system comprises a mixed-signal radio frequency (RF) receiver, the RF receiver receiving an incoming RF signal, digitizing the incoming RF signal, processing digitized data, and generating a processed digital output data, the method further comprises:

determining a delay between the analog clock signals before applying the gating signal and after applying the gating signal; and

performing uniform resampling of the digitized data after the digitizing step and before the processing step.

5. A clock masking circuit in a mixed-signal system to prevent overlapping of clock edges of one or more digital clock signals and clock edges of one or more analog clock signals, the digital clock signals and the analog clock signals being digitally controlled, the clock masking circuit comprising:

one or more timing window generators configured to generate one or more timing window pulses that are centered around the clock edges of one of the digital clock signals or the analog clock signals;

a combiner configured to combine the timing window pulses to generate a gating signal, the gating signal having an active logical level at each of the timing window pulses; and

one or more latch circuits configured to apply the gating signal to gate or delay clock edges of the other one of the digital clock signals or the analog clock signals.

6. The clock masking circuit of claim 5, wherein the one or more timing window generators are configured to generate one or more timing window pulses that are centered around the clock edges of the analog clock signals;

and the one or more latch circuits are configured to apply the gating signal to gate or delay clock edges of the digital clock signals using the gating signal.

7. The clock masking circuit of claim 5, wherein the one or more timing window generators are configured to generate one or more timing window pulses that are centered around the clock edges of the digital clock signals;

and the one or more latch circuits are configured to apply the gating signal to gate or delay clock edges of the analog clock signals using the gating signal.

8. The clock masking circuit of claim 5, wherein the mixed-signal system comprises a mixed-signal radio frequency (RF) receiver, the RF receiver being configured to receive an incoming RF signal, digitize the incoming RF signal, process digitized data, and generate a processed digital output data, the clock masking circuit further comprises:

a jitter calculator configured to determine a delay between the analog clock signals before applying the gating signal and after applying the gating signal,

wherein the delay is provided to a uniform resampler circuit of the RF receiver to uniformly resample the digitized data.