Problem with turning off eCAP submodule clock in PWMSS module.

Andrej Trnkoci

Other Parts Discussed in Thread: SYSCONFIG

Hi,

i have a problem with disabling eCAP module in a PWMSS module in a beaglebone CPU. When I try to change bits eCAPCLK_EN or eCAPCLKSTOP_REQ in a CLKCONFIG register of the PWMSS module I lose access to all PWMSS registers (even to those in eCAP, eQEP, ePWM submodules) and if following code tryies to access them the program jumps to error "data abort". With ePWM and eQEP submodules clock works everithing fine.

Does anybody know what may I be doing wrong?

Thanks

Andrej.

over 11 years ago

0 Biser Gatchev-XID over 11 years ago

TI__Guru**** 393215 points

Hi Andrej,

A module clock has to be running for the registers in that module to be accessed.

0 Andrej Trnkoci over 11 years ago in reply to Biser Gatchev-XID

Prodigy 40 points

Yes I know that but in this case I expect that bit to turn off clock only for eCAP. I am accessing only register in PWMSS module (eCAP is its submodule). So by changing bit in PWMSS module I lose access to PWMSS module what seems wierd to me. If I turn of ePWM or eQEP submodules in that register everithing is as expected (submodule stops working but I can still turn it on again in PWMSS CLKCONFIG register).

0 Biser Gatchev-XID over 11 years ago in reply to Andrej Trnkoci

TI__Guru**** 393215 points

Have you changed any of the other PWMSS main registers?

0 Andrej Trnkoci over 11 years ago in reply to Biser Gatchev-XID

Prodigy 40 points

Yes, I was configuring also PWMSS_SYSCONFIG. My current register state is in PWMSS0: PWMSS0_SYSCONFIG = 0x04 and PWMSS_CLKCONFIG = 0x101= PWMSS_CKSTATUS.

Best regards

Andrej Trnkoci.

0 Biser Gatchev-XID over 11 years ago in reply to Andrej Trnkoci

TI__Guru**** 393215 points

Try leaving PWMSS_SYSCONFIG in it's default state. Check section 15.1.3.2 in the AM335X TRM Rev. J.

0 Andrej Trnkoci over 11 years ago in reply to Biser Gatchev-XID

Prodigy 40 points

I removed all code that would change the PWMSS SYSCONFIG register. Strange is that when I enable the module, devault value in that register is 0x08 when according to TRM it should be 0x28. Also I am unable to change STANDBYMODE to 2 through CCSW memory browser. Another strange thing is that SOFTRESET in SYSCONFIG register seems to have no effect at all. If I set it to 1 it just changes to 0 and no other register changes at all. It seems to me that something what should be enabled is not, but I cannot figure out what it is.

Best regards

Andrej Trnkoci

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Problem with turning off eCAP submodule clock in PWMSS module.