Hi Brandon,

Appreciate your help. I was able to resolve the issue.

-Rakesh




On Thursday, August 14, 2014 7:28:04 AM UTC+5:30, Brandon I wrote:
>
> You have to enable the ocp master port (section 10.1.2)  to access main 
> memory. Here's an explanation 
> <http://nomel.tumblr.com/post/30006622413/beaglebone-tutorial-accessing-main-memory-from-the-pru>
> . 
>
> And, the resulting code is (if you want to do it in the pru): 
>
> // clear STANDBY_INIT bit in syscfg register so memory between pru <-> 
> system can be accessed (enable ocp master)
> LBCO r0, C4, 4, 4
> CLR r0, r0, 4
> SBCO r0, C4, 4, 4
>
> See section 3.1.2 in the pru reference 
> <https://github.com/beagleboard/am335x_pru_package> for limitations 
> (accessing memory below main memory 0x00080000 requires enabling an offset, 
> section 10.1.10).
>
>
>
> On Wed, Aug 13, 2014 at 2:02 PM, rakesh.safir <[email protected] 
> <javascript:>> wrote:
>
>> Hi,
>>
>> I want to use the DCAN interface on PRU-ICSS to send/receive data present 
>> on DDR RAM at a fixed physical address. 
>>
>>    - Address of DDR is 0x8000_0000 to 0x9000_0000(256MiB) 
>>    - My buffer is present at 0x8FF0_0000 to 0x9000_0000 (1MiB)
>>
>>  As soon as I access the hardware address 0x8FF0_0000 the PRU-ICSS goes 
>> into some faulty state and becomes unresponsive.
>>
>> Is there some other way to access DDR from PRU-ICSS ?
>>
>> Rakesh 
>>
>> On Thursday, May 16, 2013 2:42:39 AM UTC+5:30, Jason Kridner wrote:
>>>
>>> Frequently asked questions regarding "PRU":
>>>
>>>    - What is a "PRU"?
>>>    - PRU stands for Programmable Real-time Unit.  The overall subsystem 
>>>       is typically called the ICSS, PRU-ICSS or PRUSS.  ICSS stands for 
>>>       Industrial Communications Subsystem and PRUSS stands for Programmable 
>>>       Real-time Unit Subsystem. 
>>>    - What does a PRU do?
>>>       - A PRU is a 200MHz microcontroller that is really useful at 
>>>       "bitbanging" and has some peripherals attached to it that make it 
>>> well 
>>>       suited for building real-time interfaces to all types of digital 
>>>       electronics. 
>>>    - What are the processing elements within the AM33xx PRUSS used on 
>>>    BeagleBone and BeagleBone Black?
>>>       - 2 32-bit 200MHz PRU cores
>>>       - Each with 8KB of program memory
>>>       - Direct access to general purpose I/O 
>>>       - Single cycle operations without cache or pipelines 
>>>       (instructions *always* 5ns)
>>>       - Shared 12KB data memory
>>>       - Scratch pad registers
>>>       - Parallel and serial capture modes
>>>       - 32-bit port to memory and other peripherals outside of the 
>>>       PRUSS, including external memory 
>>>    - What are some example things built out of PRUs?
>>>       - DMX512 lighting protocol: http://beagleboard.
>>>       org/CapeContest/entries/BeagleBone+DMX+Cape/ 
>>>       <http://beagleboard.org/CapeContest/entries/BeagleBone+DMX+Cape/> 
>>>       - 6502 memory interface: http://elinux.org/
>>>       images/a/ac/What's_Old_Is_New-_A_6502-based_Remote_Processor.pdf 
>>>       
>>> <http://elinux.org/images/a/ac/What's_Old_Is_New-_A_6502-based_Remote_Processor.pdf>
>>>  
>>>       - Emulated memory interface on an Atari 600XL with BeagleBone 
>>>       decoding video directly into Atari 600XL display memory: 
>>>       http://www.youtube.com/watch?v=1irR4TQ5aMA 
>>>       <http://www.youtube.com/watch?v=1irR4TQ5aMA>
>>>       - Nixie tube interface: https://github.com/mranostay/beagle-nixie
>>>       - Software UART: http://processors.wiki.
>>>       ti.com/index.php/Soft-UART_Implementation_on_AM335X_PRU_-
>>>       _Software_Users_Guide 
>>>       
>>> <http://processors.wiki.ti.com/index.php/Soft-UART_Implementation_on_AM335X_PRU_-_Software_Users_Guide>
>>>  
>>>       - Sine wave generator using PWMs: http://elinux.org/
>>>       ECE497_BeagleBone_PRU
>>>       - 3D printer stepper motor driver: http://
>>>       hipstercircuits.com/pypruss-a-simple-pru-python-binding-for-
>>>       beaglebone/ 
>>>       
>>> <http://hipstercircuits.com/pypruss-a-simple-pru-python-binding-for-beaglebone/>
>>>  
>>>       - Camera interface: http://www.hitchhikeree.org/beaglebone_
>>>       capes/interacto/
>>>    - Where do I get some more details? 
>>>       - https://github.com/beagleboard/am335x_pru_package is the 
>>>       official location for documentation and tools for the PRUSS on 
>>> BeagleBone 
>>>       and BeagleBone Black.
>>>       - http://elinux.org/Ti_AM33XX_PRUSSv2 is the community wiki page.
>>>       
>>>
>>>  -- 
>> For more options, visit http://beagleboard.org/discuss
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