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GDO0 setting of CC1101-Q1

Shinya Muramatsu
Expert 1010 points
Other Parts Discussed in Thread: CC1101-Q1, CC1101

Hello, I'm FAE of distributor,and support automotive customers.

Now they are checking their board behavior,and ask us GDO0 setting.

They want to use GDO0 pin for only input,and set GDO0_CFG=0x2D.

 and GDO0 connect to output pin of external MCU.

from datasheet P58.Table 3-17 as bellow.

"GDO0_Z_EN_N. When this output is 0, GDO0 is configured as input (for serial TX data)."

Durring calibration after sending STX command from Idle mode,It seems GDO0 pin is conflict. 

We think setting GDO0_CFG=0x2D is input mode. Is it correct?

If we are Wrong,please inform us more detail what happen  setting GDO0_CFG=0x2D?

  • 0
    TI__Mastermind 36395 points
    Shinya,

    I am little confused about what you are asking for.

    1) GDO0_CFG=0x2D is "tri-state" mode.

    but then you ask about "serial TX data"

    The pin should not change configuration doing STX or calibration, can you send an oscilloscope plot of what you are seeing?

    Regards,
    /TA
  • 0
    TI__Guru* 85791 points

    Hi Shinya

    I think the comment in the CC1101-Q1 data sheet is based on an old revision of the CC1101 data sheet.

    If you look at the CC1101 data sheet you will see that the setting 0x2D is marked as reserved. The GDO0 will be configures as serial TX data input pin while in transmit mode. What you write to IOCFG0 will determine the configuration of the chip when the radio is NOT in TX mode.

    BR

    Siri

     

  • 0 in reply to Siri
    Expert 1010 points

    Hello Siri-sn.

    Thank you for explanation about datasheet. Ok,I understand setting IOCFG0=0x2D is reserved now.

    Customer want to use GDO0 as input only,because GDO0 connect to external MCU output pin and

    they don't want to change pin direction.

     In this case,My idea is that setting IOCFG0=0x2E is better. because IOCFG0=0x2E is High impedance during not transmit mode,

    and as input during transmit mode.

    They use Asynchronous serial mode TX.(0x08: PKTCTRL0.PKT_FORMAT[1:0]=0b11)

    Which IOCFG value do you recommend?

  • 0 in reply to Shinya Muramatsu
    TI__Guru* 85791 points

    Hi

    Setting IOCFG0 to 0x2E would also be my recommendation.

    BR

    Siri