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Altera_Forum's avatar
Altera_Forum
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14 years ago

High Speed time/pulse counter application

Dear Gentlemen,

I was informed from TI microcontroller application development guru that I have to use FPGA's from companies like Altera. We are developing coriolis sensor which counts pulses or time between two alternating signals. The time duration between two events varies within a few tens of micro seconds bracket we believe. That is to say we have to measure the changing time intervals with a few nano seconds of resoluion.

We think there should be a pulse with high frequency of more than a few Mherz and a counter to count the pulses between this time interval and let the counted value sent to the HMI at every few milliseconds.

What chips and technologies of Altera products and development tools for this application necessary? Please recommend the smallest versions with lowest cost for us to save time and expenses. If we will have to combine other microcontrollers to this FPGA application to get the system outputs data for HMI at every herz of the excitation frequency (100-300 Hz) then please advise about that too. If we can have solutions in Altera both the fast counting solution and HMI outputs, please do so.

To save time of writing an assembly codes from scratch, please support me with assembler code samples. Please understand we lost too much of time to fumble in in mechanical areas and microcontroller development which might be not suitable for our missions.

Best regards

Jay

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    14 years ago

    The Altera LVDS receivers can operate at up to 1Gbps, i.e., they can sample a logic signal at 1ns period (or slightly shorter). I use this scheme to interface to 1GHz clock rate ADCs, and have had no issues.

    The Altera gigabit transceivers can be operated at 3.125Gbps on the low-end Altera devices, and at up to 10Gbps on the high-end devices. I'm currently evaluating these interfaces for use at 5Gbps and higher.

    Since you only care about time, then it sounds like you could use one of these options.

    If you draw a timing diagram of the pulses, and provide specific details about what information you would like, eg., shortest pulse to expect, fastest update rate. The more accuracy you desire, the more expensive the FPGA. How did you want to gather this information; external TI microcontroller, NIOS microcontroller on the FPGA?

    If you want to look at data sheets, then the low-end FPGAs with LVDS and transceivers are the Cyclone IV GX, the Arria II GX (and I think there are versions now with V in the names), and the high-end devices are the Stratix IV and V GX (and GT).

    Cheers,

    Dave