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TMS320F28034: HRCAP

Danilo A.
Mastermind 34720 points

Part Number: TMS320F28034

Hi Team,

Can you lease help us with our customer inquiry below?

I haven't read through HRCAP of TMS320F28034. Now I can see is that the clock is PLL_CLK and capture register is 16bit.I just wonder the HRCAP can not capture slow pulses due to bit limitation?

I am considering measure pulse frequency using HRCAP

Regards,

Danilo

  • 0
    TI__Mastermind 27736 points

    Hi Danilo, 

    For capturing slow pulses, since you will have to use PLLCLK, then the max time before the counter gets overflowed would be

    2^16 * (SYSCLK) Assuming PLLCLK is 98Mhz (min freq to use HRCAP with), this would come out to be  an edge occurring at the end of  ~1.5Hz. However, if this is the case, then maybe HRCAP is not required and you can use normal eCAP with a counter register of 2^32 for slower pulses. 

    Best,

    Ryan Ma

  • 0 in reply to Ryan Ma
    TI__Mastermind 34720 points

    Hi Ryan,

    Thank you for your response. Our customer has further clarification below.

    It's nice to have your helpful reply. I just wonder whether the minimal freq to use HRCAP with is 98M hz or 98Khz.Only with 98K hz frequency,can HRCAP capture the lowest frequency of around 1.5hz.
    Thank you for your further clarification.

    Regards,

    Danilo
  • 0 in reply to Danilo A.
    TI__Mastermind 27736 points

    Hi Danilo, 

    Sorry I meant to say 1.5Khz. 

    Best,

    Ryan Ma