1 Reply Latest reply on May 11, 2020 12:51 AM by DheerajP_41

    423028-02 module GPIO internal pullup/pulldown current in sleep mode?

    ns_4270701

      Development environment:

      Windows 8.1 pro

      Platform: CYBT-423028-02

      IDE: Wiced Studio 6.2.1

       

       

      (1)On any button change on Interrupt would work even if the internal pull-up/pull-down resistor is off/disabled? and please note if there is no external pullup or pulldown resistor used.

       

      (2)How much current will be drawn by the internal pull-up resistor enabled in active mode?

       

      (3)How much current will be drawn by the internal pull-up resistor enabled in sleep mode?

       

      (4)How much latency will be for internal RTC? not used external 32Khz crystal.

        • 1. Re: 423028-02 module GPIO internal pullup/pulldown current in sleep mode?
          DheerajP_41

          Hi,

           

          1. Based on the button circuitry. we need to configure the GPIO. For example, If the button connects the CYBT-423028-02 pin to VDD when pressed, then the pin must be configured as a digital input with resistive pull-down for detecting the button press.

          It is not recommend to disable the internal pull-up/down, because the this can lead to erroneous interrupt triggers.

           

          Please check, wiced_platform_pin_config.c of CYBT_423028_EVAL platform file. Button config is as below.

          .config  = ( GPIO_INPUT_ENABLE | GPIO_PULL_DOWN ),

           

           

          2. Please check the datasheet for current numbers. https://www.cypress.com/file/414181/download  (6.5 GPIO Ports)

          All GPIO ports have programmable pull-up/down resister of approx 45K Ohms. And GPIO ports can source/sink 8 mA at 3.3 V and 4 mA at 1.8 V max. So, internal resister can consume approximately 73 uA at 3.3 V and 40 uA at 1.8 V.

           

          Note: P26/P28/P29 can sink/source 16 mA at 3.3V and 8 mA at 1.8V

           

           

          3,4. We don't have exact measurements numbers.

          In sleep mode GPIOs will be disabled and the chip will be in "Wait for Interrupt" (WFI) state. So current measurement values are not available.

           

          Please check below link to get more insight to the available clocks, timers and RTC. Firmware assumes the external LPO has lower (less than 250 PPM) error.

          CYW20719 and CYW20735 Clocks, RTC, WatchDog Timer, Application Timer and PWM

           

          Thanks,

          -Dheeraj

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