Amazing, thats is the first thing one thinks when seeing a new processor like the Propeller made by Parallax.
easyPROP is a low priced high quality Propeller based evaluation board equipped with:
- Ethernet Interface
- SD Memory
- VGA and composite Video and Audio
- PS/2 Keyboard, PS/2 Mouse
- Xbee connector
- USB Interface
- 28 I/O ports
What is so special about the Propeller processor?
- Clock Speed DC to 80 MHz
- 32K RAM / 32 K ROM, accessible by all cogs as a mutually-exclusive resource through the Hub.
- 32 I/O pins
- 40-pin DIP or 44-pin LQFP or LQFN package.
- Price: 12 dollar!!!!!
The Propeller contains eight independent processors, called cogs. Each cog contains a Processor block, local 2K RAM , two advanced counter modules with PLL’s, a Video Generator, I/O Output Register, I/O Direction register. All eight cogs are driven from the System Clock; they each maintain the same time reference and all active cogs execute instructions simultaneously. They also all have access to the same shared resources. Cogs can be started and stopped at run time and can be programmed to perform tasks simultaneously, either independently or with coordination from other cogs through Main RAM.
To maintain system integrity, mutually-exclusive resources must not be accessed by more than one cog at a time. The Hub controls access to mutually-exclusive resources by giving each cog a turn in a “round robin” fashion. There are eight lock bits (semaphores) available to facilitate exclusive access to user-defined resources among multiple cogs. Because locks are accessed only through the Hub, only one cog at a time can affect them, making this an effective control mechanism. The Hub maintains an inventory of which locks are in use and their current states; cogs can checkout, return, set, and clear locks as needed during run time.
Each cog has a video generator module that facilitates transmitting video image data at a constant rate.
The Propeller chip is programmed using Spin, a high-level object-based language, and Propeller Assembly