110 January & February 2021 http://www.elektormagazine.com
When Parallax introduced its first Propeller chip in 2006, it was
something different than what we had seen before. In recent
months, while working on the Propeller 2, Parallax has asked
users and engineers to give feedback, as the first appearance of
the chip was not in form of silicon but was given as bitstream for an
Altera DE10-Nano FPGA board. Over the time Parallax collected the
feedback and went on to get the design for the Propeller 2 in silicon.
Fortunately, the company wrote about the process in the Propeller
forum so that the community can learn about the chip manufac-
turing process. As I write this, Revision C silicon is approved for
production. Let’s take a look at the Propeller 2 and its features.
The Propeller 2
The chip is officially rated for 180 MHz clock speed, resulting in
90 MIPS per core, and every instruction takes at least two clock
cycles. Overclocking the Propeller 2 is possible and speeds beyond
300 MHz can be reached, resulting in 150 MIPS per core. When
it comes to CPU cores, your microcontroller has usually one, or
sometimes two. The Propeller 2 has eight independent cores, called
cogs, which provide a lot of computation power. All cogs share
512 KB RAM on this model, and additional 512 × 32 Bit Registers
and 512 × 32 Bit Lookup RAM per core. Besides core count and
RAM, the chip includes a whole set of interesting peripherals and
features that include:> CORDIC solver with scale-factor correction
> 16 semaphore bits with Atomic read-modify write
> 64 bit free running counter
> USB 2.0 FS host and slave interface
> Smart I/O pins (For more details, refer to the “Smart Pin
Functions” textbox.)Parallax was kind enough to send us an evaluation kit (Figure 1 ) with
a Revision C engineering sample on it, so that we could have a first
look at and start playing. So I will use this article series to give you
some insight into the chip, its peripherals, sample code, and more.A word of warning: as I write this, the chip is officially not released,
so you should expect that we will hit some rough spots when it
comes to software that might still be under construction. We were
provided with not only the evaluation board, but also a stack of
add-ons to test and play with (see Figure 2 ).Getting to Know
the Parallax Propeller 2 (Part 1)
An Introduction
By Mathias Claußen (Elektor)
Parallax put its new Propeller 2 chip — eight
cores, half a megabyte of RAM and high-
speed I/O with up to 300 MHz — into silicon.
We received an evaluation board, so let’s take
a look at the Propeller 2 and its features.embedded
Figure 1: Parallax Propeller 2 Evaluation Board Rev.C.The Propeller 2 has eight independent cores, called
cogs, which provide a lot of computation power.