• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 20 subscribers
  • Views 752 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TXS4555: Wifi router CPU connect with SIM card

Bonnie Chen
Intellectual 1150 points
Part Number: TXS4555

Hi Team,

I proposed TXS4555 to customer to connect SIM caed , but TXS4555 need RESET/CLK/IO as input.
may i know what's interface should between CPU and TXS4555?
Customer  CPU only had I2C/SPI/GPIO.

Please help to check how wifi CPU connect to sim ?

Need sim card driver ? or just translator is ok ? or cpu connect to sim directly ?

 

  • 0
    TI__Guru* 97046 points
    Hi Bonnie,
    I'm not sure what you're asking. The TXS4555 is a 3V to 1.8V SIM voltage translator -- it is used to allow a CPU operating at 3V to communicate with a SIM operating at 1.8V.

    Reset, CLK, and I/O are the standard lines used to communicate with a SIM card.... this device just converts the voltage between the processor's Reset, CLK, and I/O pins so they can communicate with the SIM card's Reset, CLK, and I/O pins.
  • 0 in reply to Emrys Maier
    TI__Intellectual 1150 points
    Hi Emrys,
    customer CPU don't have Reset, CLK, and I/O to connect to our TXS4555, how can they change GPIO or I2C or UART to Reset, CLK, and I/O?
  • 0 in reply to Bonnie Chen
    TI__Guru* 97046 points
    Hi Bonnie,
    How does the customer plan on communicating with the SIM card? Do they know how the protocol works?
  • 0 in reply to Emrys Maier
    TI__Intellectual 1150 points

    Hi Emrys,

    they don't know so they ask us. they only have I2C/UART/GPIO.

  • 0 in reply to Bonnie Chen
    TI__Guru* 97046 points

    Hi Bonnie,

    The TXS4555 provides voltage translation only for a communications channel.

    That means that it will allow two devices using the same communications protocol to communicate even though they are operating at different voltage nodes (for example, 1.8V logic and 3.3V logic)

    This device does not convert between protocols such as I2C, SPI and the SIM card standard (ETSI TS 102 221).

    I cannot go into details on the SIM card standard or how to use it since that would be considered "Engineering Services" and is far beyond the support we provide for our devices.  The customer must read, understand, and implement the ETSI standard on their own, or hire an engineer that can do it for them.

    If they have questions as to how to utilize our device, I am more than happy to help. I just cannot explain what you have asked.