A Propeller Application is a user program compiled into its binary form and downloaded to the Propeller chip’s Main RAM and, possibly, an external EEPROM. The application consists of code written in the Propeller chip’s Spin language (high-level code) with optional Propeller Assembly language components (low-level code). Code written in the Spin language is interpreted during run time by a cog running the Boot Loader while code written in Propeller Assembly is run in its pure form directly by a cog. Every Propeller Application consists of at least a little Spin code and may actually be written entirely in Spin or with various amounts of Spin and assembly. The Propeller chip’s Spin Interpreter is started in Step 3 of the Boot Up Procedure to get the application running.
Once the boot-up procedure is complete and an application is running in Cog 0, all further activity is defined by the application itself. The application has complete control over things like the internal clock speed, I/O pin usage, configuration registers, and when, what and how many cogs are running at any given time. All of this is variable at run time, as controlled by the application, including the internal clock speed.
Propeller Help Version 1.1
Copyright © Parallax Inc.
5/13/2009