P2 full datasheet badly wanted and needed
Maciek
Posts: 674
in Propeller 2
Some of us have already invested a substantial amount of time and some (not so substantial) money in the P2.
The fact is there are many documents available on the P2 scattered over many places, some of it not so up to date.
I'm not complaining but expressing a strong and genuine desire to have a FULL P2 datasheet with all the information usually found in one.
Money come and go but time spent on searching for answers that should be found in a proper datasheet we will never be able to regain.
I am sure, I'm not the only one who misses that datasheet.
The fact is there are many documents available on the P2 scattered over many places, some of it not so up to date.
I'm not complaining but expressing a strong and genuine desire to have a FULL P2 datasheet with all the information usually found in one.
Money come and go but time spent on searching for answers that should be found in a proper datasheet we will never be able to regain.
I am sure, I'm not the only one who misses that datasheet.
Comments
1. A short one for marketing listing all the features, the advantages over other µCs and the most important electrical characteristics. This one is really urgent, I think. It's bad for the P2 reputation if DigiKey lists the P2 with totally false specifications. Even the smallest and ugliest chinese shops have a link to a data sheet for every item they sell. If you can't provide a data sheet then nobody except the enthusiasts who are already here will buy it. The technical details can be left out.
2. A verbose one for the developpers. At the beginning this could be a brushed up version of the already existent silicon, and smart pin documentation. The ultimate goal should be something like the documentation for the P1 which I like very much. There are examples for every instruction with detailed explanations of special cases and so on. I'm fully aware that this takes time...
Some P2 users are finding gaps in the documentation. We presume Parallax are stretched and can't finish these right now. I wonder can we, the forum members, be more proactive and help produce that documentation ?
Chip and Ken have found time to do the Early Adopter Series of presentations / discussions, which is great. The last one on A/D conversion was good.
Is show-and-tell + pencilled drawings and sketches on a specific topic by Chip and other knowledgable people also the way to feed us 'volunteer technical authors' ? Just a suggestion - I would do some of this, if there's a few of us, so it would make a significant difference. But would it work with the detailed subject matter? As pointed out above - we've got the P1 document as framework and style guide and the 'P2 silicon' as a great jumping off point.
1. Who else is able to help?
2. What topics are most missed at present?
3 Is the documentation currently being produced, just be patient for a bit longer or
4. Does Parallax think this would work and is a 'P1 document' for P2 what's required?
https://docs.google.com/document/d/1gn6oaT5Ib7CytvlZHacmrSbVBJsD9t_-kmvjd7nUR6o/edit#
There have been many documents written by forum members over the years. Unfortunately they we’re outdated by the continual P2 design changes, and then we’re ignored by Parallax which left those authors disheartened.
In my opinion, the datasheets have to come from Parallax to have any value. If you have an IC and no instructions to allow people to put that IC to work, you don't have a complete product. Few will buy an incomplete product.
If I were doing it, I’d probably start from that...
- recommended and maximum available CPU clock,
- 1.8v current draw (vs cogs# and frequency) which I saw somewhere on the forum, then I didn't bookmark it and can't find it anymore,
- critical voltages (min and max on 1.8V line, min and max on 3.3V lines, min and max on pins) and authorized answer for a question - "can I connect 5V logic to GPIO pins via 1 (10?) kOhm resistor? (or I cannot and it will fry the P2)"
I think we need these done:
1) Electrical specs, including temperature vs. frequency performance
2) Low-level smart pin specs
Just working on the disassembler tonight for the single-step debugger.
Btw, the reason I created the datasheet in the first place was mainly so that I had a reference for hardware design. In the process of creating the datasheet I saw the need for a "typical circuit" which led to the P2D2 design (the very first P2 chip was assembled onto it as nothing else was available). The P2 chip pinout graphic was created to help make the P2 chip real, before we had silicon.
You may have heard it bemoaned many many times on the forum, but all this volunteer work is such a huge waste of our time because Parallax doesn't leverage it or even acknowledge it. It is meant to help Parallax and to help you Chip.
I don't mean to drop the ball. There's just more than I can address, it seems. I don't want for these efforts to go unappreciated, of course, but I find it hard to work on these things.
By the way, Jon Titus has written a nice paper on the smart pins, and I've proofed the first 20%, but there's more proofing needed. I've been meaning to ask on our Zoom meetings if anyone would like to pick up this effort, but I keep forgetting. I could share the document with anyone interested.
I'm up for that I think. Gaming with friends over the hols so not always around though.
In the meantime I have saved the LibreOffice document to a docx format. There are other documents in their LibreDraw format but I don't know if MSO has an equivalent.
Thanks, Evanh. I just shared it with you. It's a Google Doc. Is that going to work for you?
Thank you, Peter. I've got it loaded and I can work on it now.
Libre Office 7.0.3.1 (x64) is overlapping the last two pages (5,6) of the .docx file you posted.
Downloading last available stable version of it (7.0.4 (x64)), in order to confirm the issue has nothing to do with my side of things (it'll take a while due to my slow connection speed)...
Fully agree with you!
Initially I thought I was having a double-vision episode (uncommon with me, but, just in case), then, I've resorted to Irfanview, for a second opinion...
Understood.
a) savely without too much voltage drop?
b) absolute maximum rating without damaging the pin?
Yes, exactly my P1 manual got thick with use and abuse. I loved that book. It was well written, especially the examples and tables. Having one online is just not the same. I would pay $50 for one if it was as well written as The Propeller Manual.