XCore Exchange

leon: I think I'd be up for one your boards at that kind of price.

Do you have the necessary pins coming out for our Prop to XMOS 4 wire serial link?

I'll provide plenty of one bit ports.

Leon

Any old random 1 bit ports will not bring out the 4 wire serial link that I'm looking for for the Propeller to Xmos link.

Now I don't know which pins we can use off hand but last time I scanned through the documentation it seemed that the eternal links, serial and parallel, used pins from the middle of 16 bit port groups.

That did seemed a bit odd. I'm just off to check which pins we need again.

I was wrong about the single bit ports, two pairs of links either use two 4-bit ports, or one 8-bit port. A 16-bit port has four pairs. I'll ensure that I bring one link out to the pins - X0D4 and X0D7, say, for XLA1out and XLA1in. I might as well connect the whole of P8B to the pins, as well. This will give either an 8-bit port or two links.

It won't fit on a 0.6" wide DIL, it'll probably have to be 0.8" wide.

Leon

Corin wrote: I looked at this a while ago and designed a shcematic with a XS1-L1-64TQFP. Unfortunately due to the size of the package it won't easily fit on a 600mil wide DIP footprint.

Thanks for you posting your design. I think many of us have thought of or even had a go go at putting a board together. I know I have :)

leon_heller wrote:I'd rather make it XTAG-2 compatible, to match all future XMOS products. It'll also save the cost of an FTDI chip.

Have you considered using a 2x5W 0.1" JTAG connector instead. It should fit on a board 0.8" wide then you can have a small adapter board for the XTAG2 to 2x5W JTAG.

Thanks heater for that nugget about the 4 wire implementation and 1 bit port limitations, I didn't understand the subtlety of pin use in those sort of configs, I shall have to study these doc more closely!

Also I like TonyD idea of using a 2x5W 0.1" header is a good idea, I have seen this used in a nember of JTAGs with limited board space.

Folknology, Yeah I haven't really studied the details of the pin/port groupings yet. It just jumped out at me some time ago that using an external link buggers up an 8 or 16 bit group which seemed like a bit a disaster at the time as I wanted a 16 bit bus to an ext RAM as well. For sure not as flexible as selecting the pins on an FPGA.

Perhaps in practice it's not such a big deal in the end but you for sure need to keep yours eyes open when laying out boards.

TonyD wrote:

Corin wrote: I looked at this a while ago and designed a shcematic with a XS1-L1-64TQFP. Unfortunately due to the size of the package it won't easily fit on a 600mil wide DIP footprint.

Thanks for you posting your design. I think many of us have thought of or even had a go go at putting a board together. I know I have :)

leon_heller wrote:I'd rather make it XTAG-2 compatible, to match all future XMOS products. It'll also save the cost of an FTDI chip.

Have you considered using a 2x5W 0.1" JTAG connector instead. It should fit on a board 0.8" wide then you can have a small adapter board for the XTAG2 to 2x5W JTAG.

I might use that. The Molex connector might be better because I can put parts on the other side. I might need to do that.

I've just created a project entry.

Leon

post edited, because changed mind.
the decision is for a board with approx 40x40mm board (1.57"x1.57") and 60x40mm for the bigger version. Both have a AVR coprocessor, that can be attached on the Xlink for booting, receiving
commands/data from usb/rs232/... interface including ADC.

Hello,
you can see the first playing for making a 40x40 board, principally to see,
how it could be connected and placed. No power/reset/data-flash is inserted, only just
I/O pins. The 40x40mm one, was layouted for a single side board or double side with wires
to connect the missing vias/jumper. No vias under the package. The 40 pin dip 600mil is
made in order to check, if it´s possible to make it on double layer board. It´s seems possible.
The smaller holes are vias suitable for the connector row on the right distance. The larger
are the connector from plain lib used on the schematic for connecting the pins and on final
design, or getting removed, or (better) a smaller dedicated connector should be created instead
of the default one. Pls comment.