kicad_xmos

[myndideal]

Version: 1.1
Status: Under development
License: LGPL
Download: https://github.com/bfarago/kicad_xmos

The goal of this project to collect kicad resources for xmos dev. platform boards, library, module and sample sch, boards will be provided. In more detail:

• design new prototype boards,


• design factory ready boards,


• reuse (in a new design) another prototype platform cards like altera, xmos slice, xmos xk-1, etc. what we have at home :). 


• help each-other in community


• learn and discuss the theoretical and practical questions related to kicad tool and a cheap but industrial grade pcb manufacturing


• gathering the  know-how and design consideration 

Yes... Actually, I have several xmos boards (XK-1, XP-SKC-L2, Slice boards) already, which were good to develeop some fixtures. These are very helpful at the begining, bug fixing...

Theoretically, there is a turning point, where the prototype systems simplicity insignificant, and product like behaviours becomes more important role. Therefore, iterative design processes would be necessary to achieve the system integration level of a complex product. I hope there can be a smooth transition from hobby projects to more complex prototypes. By the way... I need some individual boards... So, I started to draw some. :) Let me know, If you have any idea... 

The basic idea is:  to get all the (free) gpio pins from the cpu board in a simply and somehow generalized interface. These connectors must be inter-changeable between cpu boards.  There have to be several different kind of break-out panels, which are implements the structural layout too.

Acutally I have some preliminary version of two similar boards for the following chips:

xs1-a16a-128-fb217

xs1-a8a-64-fb96

xe216-512-tq128

I am still playing with the design, so these are not stable, finished / accepted by me. I just wondering , how would be better....

TODO: 

• decision about connectors mechanical and electrical aspects (FFC cable / pins / board edge? pinout?)


• more footprints (U series have diff pinouts)

Actually, I just wondering if it could be possible to organise the connector pins to group by function (n*1bit, k*4bit, gnd). Because the tqfp and bga packages are totally different in layout. So it makes huge problem on routing of pcb... It means, the boards will be not pin-to-pin compatible, but function-to function compatible. 

 

Images:

[yuema]

Hi 

Did you test your design by real manufacturing , such as the function test, single integrety test....

 

 

[myndideal]

Hi,

not yet. But it is planned to be tested of course, when the main concepts are already fine.

At this moment, I just working on xmos footprints, trivial connections,  layout etc...  At the next step, I will order BOM parts for several boards, and do "manual" check again for each footprints physical dimensions, pitch, etc... Then I will ask revisions of the schematic first from others. Then I will redesign and route the PCB for a real devboard. As I mentioned I create this project to work together with others, or at least others can see my design steps, that makes possible to look forward to seen problems in an early stage. (I found only one more kicad project. Unfortunately that one still contains several trivial problems , unfixed... Therefore I started this new one. ) I spent multiple weeks to study other projects in the past. And I have a couple of years background in fpga, mcu, cpu design. So, hopefuly I can step forward in a few months. The main concept was to using only free tools, like kicad for this project. So I am somewhere around the first steps... I am using nightly build kicad, so there are several issues too... :)

The gpio pins actually just routed out for the connector(s). I have some better ideas about the connector pinouts right now. So, I will reorganize the schematic soon. The PCB layouts are not in a functional/operational state: NOT completely ROUTED in example. Because, several important decisions have to be taken before this can finished rationaly.

Furthermore, I have several test and measurement steps right now with two original XP-SKX and two XK-1A boards connected each-other. I still studing the xlink, jtag connection, doing some tests, understand the use cases, etc... 

Any ideas, and helps are welcome.

[bzyzny]

Hi, I am working on a similar project. At least, my goal is to make a simple dev board using KiCad. I was also hoping to find some way to make a standardized pin header for xmos boards, but it does seem impossible to make a pin-for-pin identical layout for the various xmos chips since the pinouts are different for each. At best, as you said, it should be possible to make a standard pin header and then map it to the unique pin layout of each mcu. What are your thoughts on using the Raspberry Pi 40pin connector layout? I was considering this since there would be a large existing collection of Hats available, however the xmos "ports" wouldn't translate well to the Rpi layout. What I am thinking of doing is to have 1 Rpi style header, using the 1bit xmos port pins, and then a seperate header designed for using the 4/8/16/32bit xmos port pins. Even that might cause headaches with routing, since the pins that make up a port are often not in order and nowhere near each other physically.

Also, I wanted to take a look at your files on github. I'm not really familiar with KiCad yet, so maybe I'm not doing it right, but when I try to open the schematic for the xe216 demo, it gives errors saying "failed to open..." and gives a popup for each of the following:

common/xlinkout1.sch

common/board1.sch

common/pwr.sch

common/xlinkin1.sch

I do not see these files in the github so maybe you forgot to include them? The schematic does open but there are parts missing.

 

[myndideal]

Hi, thank you for the comment! The missing files are just uploaded and the user lib path was modified to be relative.

I would like to warn you, these projects here only a moch-up, concept designs, only for demonstrating the kicad parts, and pcb layouts.  By the way, the goal was a lilbit more: to start some discussions about the posibilities. I would like to help the community (or to be a part of it) to specify board pinouts too. Yes, raspberryPi daughter boards are in the market a good amount, and cheap price. Therefore this is a reasonable choice. There can be other viewpoints too. For example, the chainability of a small xmos cpu boards can be a feat... I drew a lots of 3d visualization model, and discussed w one friend of mine... I did not decided about the board layouts, etc yet... 

I don't know, if it is a good way to route all of the one bits ports to one side of the board.

[myndideal]

FB236 and TQ64 footprints and xc200 components are added to the github repo.