why IRQN of CMX618 is not actived?

Discussion in 'Wireless & RF Design' started by bluexylitol, Jun 17, 2010.

  1. bluexylitol

    Thread Starter New Member

    Aug 7, 2009
    7
    0
    Dear all,

    Now I use CMX618 for an application. I have a problem that the IRQN of CBUS is not operated properly. When I send a data to CMX618 through CBUS (for example, send a data to VCFG register), if it is true, the IRQN will be pulled down;however, the IRQN is still in high logic level.

    Please help me to deal with that problem. Thank you!
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Have you read the data sheet, especially page 50? The IRQENAB register at $1F is set to determine which bits in the STATUS register will generate an IRQN.
     
  3. bluexylitol

    Thread Starter New Member

    Aug 7, 2009
    7
    0
    Thank you for your feedback.
    Although I send $8107 into the IRQENAB register ($1F), there is not falling edge in the IRQN pin of CMX618 whenever I write to VXFG, VCTRL, e.g, which according to the datasheet, this activates the IRQN is pulled down.

     
  4. bluexylitol

    Thread Starter New Member

    Aug 7, 2009
    7
    0
    I have carried out one experiment using two duplicate boards. In the first board, the IRQN always was high regardless of writing to any registers in CMX618. In the second board, the IRQN is pulled down when writing to VCFG(value=0x05) for 2400bps, 20ms packet and VDWHLWM(value=72) for low watermark=72. However, when I write to VCTRL(value=0x02 to start encoding). There is only one pulse from 3.3V to 2V. Really, I am very confused about these problems.

    I attach here a picture for illustrating these problem
     
  5. bluexylitol

    Thread Starter New Member

    Aug 7, 2009
    7
    0
    For my case, I detect that when I use polling method by reading STATUS Register of CMX618, this method is good; however, with interrupt method, the IRQN pin is always high.

    Are there any people able to help me deal this problem? I hope to get discussion about that.
     
  6. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    Have you set up the interrupts correctly? You must be sure of the interrupt priority. If it is always high, you have to change the status and/or priority bits in setup.
     
  7. bluexylitol

    Thread Starter New Member

    Aug 7, 2009
    7
    0
    I have set up high priority interrupt level and falling edge for external interrupt. The problem here is regarding to CMX618. When I write to some specified registers, such as VCTRL, VCFG, according to the datasheet, the IRQN pin is pulled down; however, the IRQN is alway high. That is my problem.
     
Loading...