Info Parallax's Propeller Home Page Getting Started Tips User Forum  Most interesting software and hardware info is to be found here (and maybe later posted to Object Exchange)!  There's a good index here. Object Exchange (Free software for Propeller) Local Index My Programming Projects The Propeller is exciting because one can easily: Drive a VGA monitor (or NTSC/PAL video monitor) to display text utilizing built-in font or graphics. Generate complex sounds, even human speech. Take user input from standard computer keyboard and mouse. Control I/O ports with 50-ns (20 MHz) precision (12.5 ns possible using internal counters). Utilize multiple internal CPUs to control multiple, independent processes. Interface via RS232, I2C, SPI Interface with keyboard, mouse, ADCs  Timing Pulse Generation (This is my initial interest regarding Propeller) 3rd Party Hardware Custom Propeller PCB Boards FAQ
	Details Manual (Bookmarked Local Copy) <--  You'll want this !!!! Datasheet (ver. 1.1)  (local copy)  (now includes speed ratings vs. temperature). Propeller is a CMOS device running at 3.3 VDC.  Extra circuitry is sometimes required to interface to 5-V logic. CPU can draw a maximum of 300 mA, dissipating only 1 W   Block Diagram:  The Propeller is a microcontroller comprising 8 independent 32-bit processors, called "cogs" Each cog can run at up to 80 MHz. All cogs share the same clock. An internal PLL allows easy operation at 80 MHz using an external 5-MHz crystal. Other, lower speed, outputs of the PLL are also selectable. There are also internal RC oscillators at 20 kHz and 12 MHz. The user's program decides what clock source to use, can be set either upon program load or programmatically while running.   Nearly all cog CPU instructions require 4 clock cycles, giving 20-MIPS operation (per cog) at 80 MHz Only instructions involving the hub take more clock cycles.  The exact number of cycles is variable, depending on hub rotational position.   Each cog has 2 kB of full speed RAM (arranged as 512 longs) Since all CPU operations work with 32-bit longs (rather than 8-bit bytes) and addresses are all words (16 bits), so it is often better to think in terms of words or longs rather than bytes for the Propeller. Cogs also have access to the much larger Hub memory (see below)   Each cog has a hardware video generator and two special counters (CTRA and CTRB) Both counters have 3 special registers (CTR, FRQ, PHS) The basic function of the counter is to add the quantity in the FRQ register into the PHS register.  When and how this is done is determined by the setting of the CTR register. Counters can operate independently from cog CPU with clock rates (controlled by CTR, FRQ registers) from 500 kHz to 128 MHz.  This done via a PLL and VCO controlled by bit PHS[31]. CTRA is used by the video generator, when the video generator is utilized.
	A "Hub" controls the cogs Hub has 32-kB RAM and 32-kB ROM  Hub controls and all cogs have access to a system counter that increments at the clock frequency Cogs interface hub memory with 16-bit address bus and 32-bit data bus. Hub maintains "Locks", a special 8-bit register accessed by special instructions. Programs that wish to use multiple cogs that may interfere with each other by attempt to access the same resources simultaneously, may wish to use these locks to ensure that only one cog has access at any given time.
	All cogs share the same 32 I/O Pins, P0-P31 and 32 direction bits Each cog has a 32 bit I/O output register and a 32-bit I/O direction register.  All 32 I/O outputs are OR'd together and all 32 I/O direction registers are OR'd together to determine actual settings. This seems to be a unique feature of the Propeller. If any cog's output is set to "1", the corresponding actual output will be a "1" The actual output of a pin is "0" only if all corresponding cog outputs are "0" If any cog's pin direction is "1", the corresponding actual pin direction with be "output" A pin's direction is "input" only if all corresponding cog directions are "0"    I/O pins P0-P27 are general purpose, but pins P28-P31 are special Pins P28-P29 are quasi-optional I2C connection (SCL, SDA) to external EEPROM Pins P30-P31 are optional serial connection (TX, RX) to a controlling computer
	Boot Sequence

1. Power or reset applied

2. After 50 ms, clock switches from 20 kHz RC to 12 MHz RC

3. Cog 0 loads and runs "Boot Loader" from hub ROM

4. Boot Loader checks for computer listening on serial port of I/O pins P30 and P31. 

   	If found, computer can either transfer a program to hub RAM and optionally to external EEPROM.  If successful, jumps to step 7, otherwise continues to step 5.
   	Computer can also instruct Propeller to suspend operation.

5. Boot Loader checks for response from EEPROM with I/O pins P28 and P29.

   If found, 32 kB is transferred from EEPROM to hub RAM.  If successful, jumps to step 7.

6. When no computer host found and no EEPROM found, cog 0 is stopped, all I/O pins set to input mode, and Propeller goes into shutdown mode.

7. After successfully loading a program into hub RAM (and not instructed by computer to suspend):

   1. Cog 0 loads and runs the "Spin Interpreter" code from hub ROM

   2. Spin Interpreter executes code in hub RAM 

Boards & Kits

There are two boards available from Parallax, Demo and Proto: Demo board is ready to go with VGA, sound, keyboard, mouse, USB, and power connectors Schematic:    Photo:  Optional kit with keyboard, mouse, and display available   Proto board is more basic (but cheaper and more versitile): Documentation  Schematic:   Photo:  Optional kit has the resistors and connectors you need for VGA, mouse and keyboard.

Parallax also offers the Hydra game development kit (so you can make your own 80's style arcade games)

Programming New! Prop Tool 1.25 available Programming done via serial connection (normal or USB) with Parallax's "Propeller Tool" Windows program.  A program can consist of high-level "Spin" language code "objects" and low-level assembly code. Assembly code is optional, but some Spin code is required in all apps. The Propeller Tool comes with many examples. One key point is that you must select a "top" Spin object in the software, which defines the main procedure that runs first.  Then, you can either "Run->Compile Top->Load RAM" or "->Load EEPROM".  If you load RAM the program runs, but is erased by power loss or reset.  If you load EEPROM the program is retained even after power loss and restarts after reset or restoration of power. Parallax maintains an "Object Exchange" library of copyright free user contributed code objects. A great deal of code can be found by digging through the user forum. Debugging can be difficult.  Many people seem to be using a terminal window on the PC and the "FullDuplexSerial" object to send messages to the PC.