Fwd: PRU FAQ 2013-05-15

[Drew Fustini]

---------- Forwarded message ----------
From: Stephan Kulov <lordst...@gmail.com>
Date: Wed, May 29, 2013 at 11:51 PM
Subject: Re: PRU FAQ 2013-05-15
To: Drew Fustini <pdp7...@gmail.com>
Cc: Ed Bennett <e...@kineticsandelectronics.com>, Jay Hopkins <iwa...@gmail.com>


This line has "real-time DSP" written all over it:
Single cycle operations without cache or pipelines (instructions *always* 5ns)

On Wed, May 29, 2013 at 1:03 PM, Drew Fustini <pdp7...@gmail.com> wrote:

fyi:

On Wednesday, May 15, 2013 4:12:39 PM UTC-5, 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/
• 6502 memory interface: 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
  
• 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
• 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/
• 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.