Difference between GPIO EMC, SD, AD and no descriptor

[Shruti1]

Hello,

When setting the pinmux setting for PWM in RT1062, I am looking through the fsl_iomuxc.h file. For Pwm2 A3, I see:

IOMUXC_GPIO_EMC_19_FLEXPWM2_PWMA03

IOMUXC_GPIO_AD_B0_00_FLEXPWM2_PWMA03

IOMUXC_GPIO_AD_B0_09_FLEXPWM2_PWMA03

IOMUXC_GPIO_B1_02_FLEXPWM2_PWMA03

IOMUXC_GPIO_SD_B1_02_FLEXPWM2_PWMA03

For other PWM ports and pins, I see multiple pins as well. How do I determine which is the correct one to use? I need to use all four PWMs (4-8 channels in each). 

Thanks.

[Shruti1]

Thanks Kerry for your response. If you look at the list above:

IOMUXC_GPIO_B1_02_FLEXPWM2_PWMA03

IOMUXC_GPIO_SD_B1_02_FLEXPWM2_PWMA03

1. Are these for the same pins, or are they different pins?

2. What is the difference between the "EMC" pins? PWM3 and PWM4_Bonly has EMC pins in the fsl_iomuxc.h file. Can I use those?

Thank you.

[Shruti1]

Yes, this helps a lot. Thank you.

[kerryzhou · Accepted solution]

Hi @Shruti1 ,

IOMUXC_GPIO_B1_02_FLEXPWM2_PWMA03

IOMUXC_GPIO_SD_B1_02_FLEXPWM2_PWMA03

1. Are these for the same pins, or are they different pins?

=>Answer: Totally not the same pin, the different pin.

2. What is the difference between the "EMC" pins? PWM3 and PWM4_Bonly has EMC pins in the fsl_iomuxc.h file. Can I use those?

=>Answer: EMC pins normally used for the SEMC, which is used for the external memory, eg, SDRAM.

If you don't use the related EMC pins, you can use it on your side, just check your board, make sure the pin is valid for use in the HW.

Wish it helps you!

Best Regards,

Kerry

[kerryzhou]

Hi @Shruti1 ,

    From the RM, pin, you can find:

each PWM can support several pins, you can choose the pin which your board is avaiable, then configure that one.

Eg, IOMUXC_GPIO_AD_B0_09 is available, then you can use this pin.

Determined by your hardware situation.

Best Regards,

Kerry