Pulse Width Modulation

Pat Doyle

Hello Everyone,

I am trying to create a Pulse Width Modulation output on the AM389x. The pins TIM4_OUT, TIM5_OUT, TIM6_OUT, TIM7_OUT, can be set as PWM according to datasheets. I can see no guidance on how this is done. There seems to be no software driver that support PWM on the Evaluation Module.

over 14 years ago

0 Pat Doyle over 14 years ago

Prodigy 40 points

Here is some more information as I dig deeper.

I am looking at the details in AM389x Sitara ARM Microprocessors (MPUs) Technical Reference Manual (http://www.ti.com/lit/ug/sprugx7/sprugx7.pdf ).

Tracing that to the Linux PSP I am looking at arch/arm/mach-omap2/omap_hwmod_ti81xx_data.c. I think I need to add code to configure PWM. Am I looking in the right area? I know that there is a relationship with timers, so perhaps I should be looking at AM389x timer operation - but don't know where or how. Again if anyone has gone through setting up PWM/Timer all help would be appreciated.

0 MarcPyne over 14 years ago

TI__Mastermind 25055 points

Hello,

Unfortunately we do not have a SW driver for PWM support.

Regards,
Marc

0 Pat Doyle over 14 years ago in reply to MarcPyne

Prodigy 40 points

Marc, Is there any software support for timers?

Regards,

Pat

0 MarcPyne over 14 years ago in reply to Pat Doyle

TI__Mastermind 25055 points

Pat,

The drivers available may depend on which PSP version you are using. Please refer to the Release Notes for a description of the drivers available in that release.

http://processors.wiki.ti.com/index.php?title=DM81xx_C6A81xx_AM38xx_Linux_Releases#PSP_04.00_Releases_-_support_for_DM816x.2C_C6A816x_and_AM389x_devices

Regards,
Marc

0 Pat Doyle over 14 years ago in reply to MarcPyne

Prodigy 40 points

Marc,

Thanks for that I am using PSP 04.00.00.12.

For any other readers interested, here is the link to the modules used:-

http://processors.wiki.ti.com/index.php/DM816x_C6A816x_AM389x_PSP_04.00.00.12_Feature_Performance_Guide#Module.2FSubsystem_Usage

There is no timer5-7 configured. Is there a roadmap of additional features and where can I find information about it? Is support for timers5-7 being considered?

Regards,
Pat

0 MarcPyne over 14 years ago in reply to Pat Doyle

TI__Mastermind 25055 points

Pat,

I know it is planned, but I'm not sure when. Please contact your local TI Representative and they can get you the latest PSP roadmap information.

Regards,
Marc

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Pulse Width Modulation