Re: [9fans] JTAG

[EBo <ebo@sandien.com>]

 Gorka,

 This all sounds good.  I wish you luck...

   EBo --

> The way I think this works:
>
> USB-MPSSE-JTAG-uP
>
> The USB part is a simple protocol which I already have figured out
> and is
> in the driver's .h.
> http://yosemitefoothills.com/Electronics/FTDI_Chip_Commands.html
>
> I am now looking into the MPSSE details which is a
> kind of programmable controller for the JTAG which has high level
> commands
> so that operations do not take a round trip through USB.
>
> For this the best docs I found are the openocd code and some
> documents
> referred in it:
> http://www.ftdichip.com/Documents/AppNotes/AN2232C-01_MPSSE_Cmnd.pdf
> http://openocd.berlios.de/web/
>
> The openocd code is my main reference because it does work on linux.
> If I have to I'll resort to sniffing the USB connection in linux,
> though I hope
> it does not come to that.
>
> After the MPSSE (or at the same time)
> I have to figure the JTAG part for which probably EBo's references
> are good,
> I haven't figured that part at all. Then there is an standard for
> arm called ICE something or other (apparently there are different
> names and
> interfaces for different versions of arm) which lets you look at the
> different
> registers of arm and do interesting things to it. Then there is how
> the JTAG is
> cabled inside the SoCer itself:
>
>
> http://www.marvell.com/products/processors/embedded/kirkwood/HW_88F6281_OpenSource.pdf
>
> I am working my way slowly through this sorry if this a tad
> incoherent, but I haven't
> figured most of it yet.
>
> G.