F2805x ePWM

Ssu-Han Huang

Dear all,
I have a little question. I wanna know what will the pin become before the PWM counter start to run?Is it low, high, or tristate? What kind of register may I set for those setting?

Thanks all

M.W.

over 12 years ago

0 Gautam Iyer over 12 years ago

Guru 192875 points

Hi,

Go through the respective PWM user guide for your controller:

http://www.ti.com/lit/ug/spruhe5b/spruhe5b.pdf

Regards,

Gautam

0 David M. Alter over 12 years ago

TI__Guru 61235 points

Ssu-Han,

You do not say which specific pin you're talking about, but I assume it is one of ePWM1a through ePWM6b, which are shared with GPIO0 to GPIO11 on the F2805x. After reset, these pins all default to GPIO input mode (i.e., tri-state). These pins have an internal pullup, but on GPIO0-11 the pullup is DISABLED after reset (see SPRUHE5B, p.109). The pullups were deliberately disabled by default on the PWM pins so that users can apply an external resistor and choose their own default state (i.e. high or low) based on the requirements of their application.

After you configure the the PWM module, the pin will be however you specified in the Action Qualifier Register (AQCTLx) based on the time base counter register.

Regards,

David

0 Ssu-Han Huang over 12 years ago in reply to David M. Alter

Prodigy 210 points

Thanks a lot David, thanks!

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F2805x ePWM