i.MX Processors中的主题 GPIO Pulldown IMX6SL

GPIO Pulldown IMX6SL

stephangm — Thu, 26 May 2016 18:47:32 GMT

How can I set a GPIO pin to be a pulldown without using an external resistor?

Re: GPIO Pulldown IMX6SL

Carlos_Musich — Thu, 26 May 2016 23:16:01 GMT

Hi Stephan,

do you want to do it in bareboard code? Modifying directly the registers? In this case you must check the Pad Control Register (IOMUXC_SW_PAD_CTL_PAD_AUD_MCLK). Here you will find the following options for a pin:

00 100K_OHM_PD — 100K Ohm Pull Down

01 47K_OHM_PU — 47K Ohm Pull Up

10 100K_OHM_PU — 100K Ohm Pull Up

11 22K_OHM_PU — 22K Ohm Pull Up

If this is not what you are looking for please let me know details of what you need to configure so I can provide more details.

Regads,
Carlos

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

Re: GPIO Pulldown IMX6SL

art — Mon, 30 May 2016 12:13:09 GMT

An internal 100kOhm pull-down resistor can be enabled on most of GPIO pins by appropriately configuring the corresponding IOMUXC_SW_PAD_CTL_PAD_<xxx> register, where <xxx> is the corresponding pin name. The sequence is as follows.

1. Set the IOMUXC_SW_PAD_CTL_PAD_<xxx>[PUS] bits to 0b00 to select the 100kOhm pull-down resistor.

2. Set the IOMUXC_SW_PAD_CTL_PAD_<xxx>[PUE] bit to 1 to enable the pull resistor (not a keeper circuit).

3. Set the IOMUXC_SW_PAD_CTL_PAD_<xxx>[PKE] bit to 1 to physically enable the pull resistor.

For more information, refer to the Chapter 30 "IOMUX Controller (IOMUXC)" of the i.MX6SoloLite Reference Manual Rev.2 document, available on the i.MX6SoloLite Documentation web page:

http://www.nxp.com/products/microcontrollers-and-processors/arm-processors/i.mx-applications-processors/i.mx-6-processors/i.mx6qp/i.mx-6sololite-processors-single-core-low-power-epd-controller-arm-cortex-a9-core:i.MX6SL?fpsp=1&tab=Documentation_Tab

Have a great day,
Artur