RTOS/BEAGLEBK: PRU access to RTC

Hildo Guillardi Junior

Part Number: BEAGLEBK

Tool/software: TI-RTOS

Checking the BeagleBoneBlack schematic and the AM3358 datasheet is possible to see that the Sitara have a RTC module (Real Time Clock for calendar information). In the ARM Cortex (Linux) this may be accessed transparently by the OS (confirm me if don't).

But, is it possible to read the RTC information by one of the PRU cores?

over 6 years ago

0 Biser Gatchev-XID over 6 years ago

TI__Guru**** 393215 points

Yes, the RTC is accessible from the PRU-ICSS, however you must ensure that access is not locked by a driver running on the main ARM.

0 Hildo Guillardi Junior over 6 years ago in reply to Biser Gatchev-XID

Prodigy 200 points

How do I access it? (There is some TI example? At least about 'how to access peripheral of Sitara by PRU' that I can modify addresses and use).

0 Nick Saulnier over 6 years ago in reply to Hildo Guillardi Junior

TI__Guru 72495 points

Hello Hildo,

Please see this post for an example of reading values from a peripheral's registers. The code was written for PRU in a a Linux environment, but I think the firmware code for the PRU should be the same in an RTOS environment.

Basic steps: 1) allow OCP master port access by the PRU. 2) perform any peripheral initialization that may be required. 3) Access the desired memory addresses.

Regards,

Nick

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RTOS/BEAGLEBK: PRU access to RTC