How to access ELLOW protected HRCNFG register of eHRPWM module in OMAPL138 ?

Sugumar Natarajan

Other Parts Discussed in Thread: OMAPL138

Hello,

I am trying to implement the high resolution feature of eHRPWM module in OMAPL138. It is mentioned in the data sheet that HRCNFG register is EALLOW protected and a special instruction should be used to access the register. I could not find the related information in the OMAPL13x/AM18xdatasheet . Kindly let me know if any special procedure needs to be followed to access the register.

http://focus.ti.com/lit/ug/sprufu7/sprufu7.pdf

Regards,

N.sugumar

over 14 years ago

0 clam over 14 years ago

TI__Expert 8785 points

This is a typo in the user guide. There is no EALLOW protection for the register. You should be able to access it like any other peripheral MMR register.

--Christina

0 Sugumar Natarajan over 14 years ago in reply to clam

Intellectual 670 points

I am unable to access the HRPWM registers. The register always read back as zero irrespective of what ever value is written into the register. The same behavior results for all the 3 registers of High-Resolution PWM Submodule Registers . But i am able to successfully program the other sub modules such as timer ,counter and action control sub modules. Is there any special configuration needs to be done to enable High-Resolution PWM Submodule ?

0 tlee over 14 years ago in reply to Sugumar Natarajan

TI__Guru 62975 points

Sugumar,

Please verify that you have enabled the modules through the Power and Sleep Controller (PSC) registers. The EVM gel file includes examples of enabling modules.

-Tommy

0 clam over 14 years ago in reply to tlee

TI__Expert 8785 points

After doing some testing, I found out that the user guide has the incorrect offset for the HRCNFG register. The correct offset is 0x1040. I'll send a request to get it corrected in the next revision of the user guide.

--Christina

0 Sugumar Natarajan over 14 years ago in reply to clam

Intellectual 670 points

Christina,

Thanks. Now i am able to access the register. Also , could you confirm the the offsets of other registers TBPHSHR and CMPAHR. I could not access those registers as well.

Regards,

N.Sugumar

0 clam over 14 years ago in reply to Sugumar Natarajan

TI__Expert 8785 points

The TBPHSHR and CMPAHR register offsets are correct.

For example, for EPWM0

Base Address: 0x01F0 0000
TBPHSHR: 0x01F0 0004
CMPAHR: 0x01F0 0010
HRCNFG: 0x01F0 1040

--Christina

0 Sugumar Natarajan over 14 years ago in reply to clam

Intellectual 670 points

Christina,

Thanks for the clarification. Actually i was accessing 0x1010 instead of 0x0010 .

Regards,

N.sugumar

Processors

Processors forum

How to access ELLOW protected HRCNFG register of eHRPWM module in OMAPL138 ?