View Full Version : An interesting observation

09-15-2007, 08:18 PM
It is Saturday.

We were discussing some interesting topics. I happened to mention that I am in love with a new chip. People stared at me - not believing they heard me right. I explained. Got a piece of paper and drew a sketch explaining the Propeller architecture...

I than dawned upon me: Hey! I am drawing this complete architecture just like that - from the top of my head. Never done that before. What's going on here?

Simple. With such a straightforward and uncluttered design, there's not much to memorize. It just comes naturally. That is also a quality that not many other chips have.

Had to share...


Graham Stabler
09-15-2007, 08:21 PM
I hope you drew it on either the back of an envelope or a napkin!

A window is almost as good for geek status, UV pen optional.

But seriously it does have a certain elegance.


09-15-2007, 10:23 PM
I did the same on a white board earlier this month, stating the same thing. (pathetic geek chip lust)

Never thought about it, but you are right! I've never diagrammed a chip like that for discussion before. Networks, data structures, etc... all see frequent diagrams, but never CPU's.

Where did your conversation go, after that? In mine, I found after laying out the chip, the discussion settled on multi-processing and parallism. Differentiating the Prop, from other things like multi-core, NUMA, those networked clusters I can't seem to remember the word for, etc... proved difficult.

The idea of dedicating COG's to tasks, to form what I like to call 'sardware' appeals quickly. People grok that. IMHO, that's probably the easiest selling point to get across. (Which is why I really like, "The Power of 8" for the new slogan.)

Determinism proved much more challenging. The average person, interested in this stuff, will almost always ask, why not just have one fast CPU, then these COG's? Or they ask, why have so much on the chip? Of course, the reality is there isn't that much on chip, it's just very easily re purposed!

Just wondering where that thread went for you Skogsgurra. What did they grok right away, and what proved hard?

Propeller Wiki: Share the coolness! (http://propeller.wikispaces.com/)

09-15-2007, 10:52 PM
Some years ago, I went through a naval electronics training course and one of the classess was "Digital Microproccesors" or some such thing. When we entered the class, the most striking feature was a huge schematic which covered most of 3 entire walls. During the first session we told that by the end of the course we'd understand every feature of the the entire schematic. That schematic was a single 8088 microprocessor! That 8-bit cpu was barely capable of being a descent calculator. Long live the Propeller!

09-16-2007, 12:16 AM
It was a mistake to bring it up at all. These people are "normal" people. They take everything for granted. They seemed to be more interested in discussing the availability of mushrooms and cranberries in the forest we live in, the neighbour's cat and such things. They are used to me - I am kind of a bore in their eyes. :-(


09-16-2007, 03:19 AM
The 8088 is not an 8 bit uP. Maybe you intended the 8080 or the 8008. The 8080 had DAA (if I'm not mistaken), so you can do a decent calculator (The TI-80..TI-86 are based on the z80 that as yuo know is descendant of the 8080). Old calculators had special purpose uP. Nowadays, they have 6502 variants (also has DAA, decimal adjust after addition/subtraction, btw he 8088 has it also). But without it and with a bit more work, you can have functional BCD arithmetic (for AVR implementations check the atmel app notes for atmegas, if you want some functional examples, ask me, I have jede menge).

I stopped caring what "normal" people think of me or of people like me. I like chemistry, electronics, history, languages.. and pr0n. If they don't, I can't help them http://forums.parallax.com/images/smilies/devil.gif http://forums.parallax.com/images/smilies/jumpin.gif http://forums.parallax.com/images/smilies/lol.gif

Post Edited (Ale) : 9/15/2007 8:24:57 PM GMT

09-16-2007, 03:58 AM
I like discussions like these... And I am more often in situations Skogsgurra describes rather than in Potahead's circles http://forums.parallax.com/images/smilies/smile.gif
Discussions go wrong when you do not distinguish between:

- What current technology can do ("I shall now show you a movie where people repair the ISS space station")
- What you can buy for resonable money ("Look at this 3 Euro MP3 player with display and storage for 1000000 songs")
- What you have done yourself ("Here is my new 'Turtle Robot': It will obey to the commands: 'Come', 'Hide', and 'Play Music")

Maybe a Propellor is involved in each of these scenarios, or not - I have never managed to explain the significance of this design layer.