How to get started with startKIT

All technical discussions and projects around startKIT
User avatar
fosfor
Member
Posts: 11
Joined: Wed Jul 04, 2012 5:08 pm

Re: How to get started with startKIT

Postby fosfor » Sun Jan 05, 2014 2:24 am

Lefty4000 wrote:The startKIT actually uses its own custom chip. One that has its own voltage regulators internal to the chip which allows for the startKIT to be as cheap as it is.
XS1-U16A-128-FB217 also has its own DC-DC convertors. See datasheet, chapter 14.
Lefty4000 wrote:I believe it to be based off of the XS1-A8A-64 which only has 8 cores at 500MIPS. This is because of what is stated in the startKIT hardware manual on page 3
There are several diferences with XS1-A8A-64, e.g.:
  • A8A doesn't have USB, 8A6C5DEV has
  • A8A has only one tile (8 cores), 8A6C5DEV has two (16 cores)
  • A8A doesn't have pin U19, 8A6C5DEV has
User avatar
Lefty4000
Active Member
Posts: 32
Joined: Mon Nov 11, 2013 6:17 pm

Postby Lefty4000 » Sun Jan 05, 2014 2:35 am

The chip only has 8 cores (1 tile)
The chip is special which does have USB
The chip does have pin U19 mapped to the debug header (startKIT Schematics)
startKIT provides a single programmable 500 MIPS xCORE tile with eight logical
cores. All the digital I/O have been brought out to pins providing many combinations
of peripherals to be integrated with the startKIT board. The A8-DEV board
also includes an integrated debugger.
From the startKIT Hardware Manual

Watch this video, at about 1:15, he explains it all
http://www.xmos.com/en/startkit#D1WEaWZP
Its 500MIPS xCORE multicore microcontroller has eight 32bit logical cores that perform deterministically, making startKIT an ideal platform for functions ranging from robotics and motion control to networking and digital audio.
From the startKIT Home page: http://www.xmos.com/startkit
User avatar
Bianco
XCore Expert
Posts: 754
Joined: Thu Dec 10, 2009 6:56 pm

Postby Bianco » Sun Jan 05, 2014 1:16 pm

The startKIT uses a XS1-U16A-128-FB217 like been said many times :).
One tile and the USB PHY is reserved for the onboard debugger.
It is advertised as a single tile device because XMOS does not want you to think it has 2 tiles because the other one is not (or hard :p) to be usable for end users anyway since it is dedicated for the debugger.
User avatar
Lefty4000
Active Member
Posts: 32
Joined: Mon Nov 11, 2013 6:17 pm

Postby Lefty4000 » Sun Jan 05, 2014 6:43 pm

Where is this documented?
User avatar
segher
XCore Expert
Posts: 843
Joined: Sun Jul 11, 2010 1:31 am

Postby segher » Sun Jan 05, 2014 6:55 pm

It is not (directly) documented. Note that the wording in
the documentation you quoted is careful not to claim there
is only one processor.

If you look at the pinout of the A8-DEV (in the startkit
schematic) you see it matches 1-1 with the U16.

Finally, let's use our eyes: it obviously is an FB217 (count
the pins); and the package says "S2".
linuxguru
New User
Posts: 2
Joined: Mon Dec 16, 2013 1:04 pm

Postby linuxguru » Sun Jan 05, 2014 7:20 pm

Phrewfuf wrote:Damn, there goes my plan on building an audio device :(
Same initial reaction as mine - BTW, you can still do a 24/192 S/PDIF to I2S converter with a StartKit, and use it to drive an external WM8727 or ES9023 DAC - it needs just 1 input and 4 outputs.
User avatar
Lefty4000
Active Member
Posts: 32
Joined: Mon Nov 11, 2013 6:17 pm

Postby Lefty4000 » Sun Jan 05, 2014 8:07 pm

Hmm.

Now I feel stupid. That is definitely misleading though.
User avatar
Bianco
XCore Expert
Posts: 754
Joined: Thu Dec 10, 2009 6:56 pm

Postby Bianco » Sun Jan 05, 2014 8:21 pm

What is misleading? There are many many starter kits from other vendors that only include a USB interface for debugging.
User avatar
Lefty4000
Active Member
Posts: 32
Joined: Mon Nov 11, 2013 6:17 pm

Postby Lefty4000 » Mon Jan 06, 2014 6:36 am

what?

No the amount of cores. They plaster "eight cores" everywhere so everybody assumes, "Okay, this thing is an eight core device". Not many people are going to question that when it seems so absolute.

Not a big deal, but I feel like that should be noted somewhere.
User avatar
Bianco
XCore Expert
Posts: 754
Joined: Thu Dec 10, 2009 6:56 pm

Postby Bianco » Mon Jan 06, 2014 8:41 am

Well it is an 8-core device for 99.99% of the people concerned.
It would be misleading to advertise it as a 16-core device while 8 of them are not (trivially) usable to the programmer. It is misleading when companies promise more and deliver less. I see many people concerned about the exact chip or datasheet. Frankly enough this isn't all that important on the XMOS arch for programmers. Almost all info needed is in the startKIT hardware manual (the port map being most important) and the other generic documents like the XC programming manual, The XS1 architecture manual etcetera.

Who is online

Users browsing this forum: No registered users and 2 guests