We are pleased to announce that as of August 13, 2015, Qualcomm Global Trading Pte. Ltd., a subsidiary of Qualcomm Incorporated, has completed its acquisition of CSR plc. For more information, please see the press release .


SiRFInstantFix™ satellite prediction technology greatly improves start-up times for any location-centric device - with or without internet accessibility.

Start-ups between 5-10 seconds are made possible by employing a small Extended Ephemeris file, either acquired via the internet generated by a server (Server Generated Extended Ephemeris-SGEE) or calculated on the device (Client Generated Extended Ephemeris-CGEE), far outlasting a standard broadcast ephemeris by 3 to 31 days. SiRFInstantFix SGEE and CGEEII is supported on most CSR GPS chips.

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  • Time To First Fix
    - 5-<10s
  • Memory
    - Data segment 216 KB (RAM
    - Read-only segment 48 KB (ROM
    - Text segment 176 KB (ROM)
  • SGEE File Size
    - Approximately 11kB/day of
    prediction for GPS
    - Approximately 8.6kB/day of
    prediction for GLONASS
  • Supported Chips
    - SiRFstarIII/IV/V
    (GLONASS requires SiRFstarV™)
    - SiRFPrima / SiRFatlas SoCs



SiRFInstantFix provides exceptional start-up times with or without connectivity

With connectivity (SGEE)

  • Speedy start-ups are made possible via an internet connection that eliminates the need to download a satellite ephemeris, allowing a SiRF® receiver to be instantly navigating in almost any environment
  • The key to this solution is a sophisticated set of proprietary algorithms that calculate an Extended Ephemeris (EE) file, yielding an accurate fix long after a traditional broadcast ephemeris has timed out—about four hours—and provide navigable positions for up to 31 days

Without connectivity (CGEE)

  • Fast start-ups are made possible with one observation of each satellite, accurately predicting satellite positions for up to three days—removing the need to download satellite ephemeris data at subsequent start-ups
  • SiRFInstantFix CGEE software resides on the host processor of SiRFstar-based PNDs, and can run as a low priority background task. On SiRFprima & SiRFatlas, SiRFInstantFixII  CGEE software resides on the SoC

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