Crystal oscillator emulator with externally selectable operating configurations

• US 9,143,083 B2
• Filed: 11/25/2013
• Issued: 09/22/2015
• Est. Priority Date: 10/15/2002
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Sutardja, Sehat
• Primary Examiner(s): GRAYBILL, DAVID E
• Application Number:
  US14/089,261
• Publication Number:
  US 20140077891A1
• Time in Patent Office: 666 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G11C 5/00 Details of stores covered by group G11C11/00
• CPC Class Codes: G11C 5/143 Detection of memory cassette insertion or removal; Continuity checks of supply or ground lines; Detection of supply variations, interruptions or levels G11C5/148 takes precedence; Switching between alternative supplies G11C5/141 takes precedence
• CPC Class Codes: H01L 2224/05553 being rectangular
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 23/315 the encapsulation having a cavity
• CPC Class Codes: H01L 23/345 Arrangements for heating thermal treatment apparatus H01L21/00
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/19041 being a capacitor
• CPC Class Codes: H01L 2924/30107 Inductance
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H03B 5/04 Modifications of generator to compensate for variations in physical values, e.g. power supply, load, temperature
• CPC Class Codes: H03B 5/36 active element in amplifier being semiconductor device H03B5/323, H03B5/326 , H03B5/38 take precedence
• CPC Class Codes: H03L 1/026 by using a memory for digitally storing correction values H03L1/025 takes precedence
• CPC Class Codes: H03L 1/027 by using frequency conversion means which is variable with temperature, e.g. mixer, frequency divider, pulse add/substract logic circuit H03L1/023, H03L1/026 take precedence
• CPC Class Codes: H03L 1/04 Constructional details for maintaining temperature constant
• CPC Class Codes: H03L 7/07 using several loops, e.g. for redundant clock signal generation
• CPC Class Codes: H03L 7/0891 the up-down pulses controlling source and sink current generators, e.g. a charge pump
• CPC Class Codes: H03L 7/099 : concerning mainly the controlled oscillator of the loop
• CPC Class Codes: H03L 7/1976 : using a phase accumulator for controlling the counter or frequency divider

Abstract

A crystal oscillator emulator having a plurality of predetermined operating configurations. The crystal oscillator emulator includes a measurement circuit configured to measure a value of an impedance connected to a select pin of the crystal oscillator emulator, wherein the impedance is external to the crystal oscillator emulator, and generate an output having a value corresponding to the value of the impedance. The storage circuit is configured to store a plurality of values corresponding to the plurality of predetermined operating configurations and select one of the plurality of values based on the output of the measurement circuit. A controller is configured to set an output frequency of the crystal oscillator emulator based on the selected one of the plurality of values.

Claims

1. A crystal oscillator emulator having a plurality of predetermined operating configurations, the crystal oscillator emulator comprising:

a measurement circuit configured to (i) measure a value of an impedance connected to a select pin of the crystal oscillator emulator, wherein the impedance is external to the crystal oscillator emulator, and (ii) generate an output having a value corresponding to the value of the impedance;

a storage circuit configured to i) store a plurality of values corresponding to the plurality of predetermined operating configurations, and (ii) select one of the plurality of values based on the output of the measurement circuit; and

a controller configured to set an output frequency of the crystal oscillator emulator based on the selected one of the plurality of values.

2. The crystal oscillator emulator of claim 1, wherein, to measure the value of the impedance, the measurement circuit is configured to measure (i) a voltage across the impedance, and/or (ii) a current through the impedance.

3. The crystal oscillator emulator of claim 1, wherein the output of the measurement circuit has a digital value.

4. The crystal oscillator emulator of claim 1, wherein the output of the measurement circuit corresponds to a range of values of the impedance.

5. The crystal oscillator emulator of claim 1, wherein the storage circuit is configured to select the one of the plurality of values as a function of the output of the measurement circuit.

6. The crystal oscillator emulator of claim 1, further comprising an address generator configured to determine a memory location of the storage circuit corresponding to the output of the measurement circuit, wherein the storage circuit is configured to select the one of the plurality of values corresponding to the memory location.

7. An integrated circuit including the crystal oscillator emulator of claim 1, wherein the select pin is an external pin of the integrated circuit.

8. The integrated circuit of claim 7, further comprising:

a decoder configured to detect signals on the external pin.

9. The integrated circuit of claim 7, further comprising:

a phase lock loop configured to generate an output signal based on the output frequency.