XCore Exchange

That tag-connect cable assembly is pretty cool!
At this point I am leaning towards in-circuit programming so something like that has appeal.

I looked through that thread you linked. good info there. (I used to work with DHembree.)

I have not started schematic yet but I have done most of the background work so should go pretty quick.
Still fuzzy on programmer and programming. Based on what I can gather from what you have said (correct me if I'm wrong)...
- XFLASH does not have QSPI capability
- StartKit works to program chips before getting stuffed.

I'm wondering if XTAG and Composer will work.

Looks like several of the flash chips recommended have EOL notices or not manufactured anymore.

correction - XFLASH works just takes a while

XFLASH can support QSPI programming but you will need to have the QSPI port pins so need a CPU from the XCORE-200. One of the threads here discusses to just buy a XCORE-200 based kit, hot air off the SMD flash device -> place your fresh device -> use XFLASH to program the target in QSPI mode. The XFLASH tool, if it is informed to operate in QSPI mode, will program the QSPI bit.

The issue is that XCORE-200 was designed to use QSPI mode for R/W access of the flash but StartKit was not so the pins are not compatible across the programming code. However, you can certainly use other free pins on the StartKit to apply QSPI mode.

Keep in mind that a QSPI flash device is able to be programmed using standard (slower) SPI commands. Just that it will take longer to perform the same task.

StartKit is one, low cost way to program the SPI flash. Buy the kit, hot air remove the flash device and then program again using standard SPI commands. StartKit cannot program using the QSPI mode since the port pins are not mapped like the XCORE-200 device is. However, no issue to program the target slowly and then enable the QSPI bit. In the end, it all works fine. We have validated this and another developer in Vietnam recently followed the same method to be operational.

Would you have access to SMD hot air tools? That will be nice to have. Plan B is to source a 8 pin SOIC to DIP adapter (Adafruit, etc. are low cost) from Digikey and then use the free pins on the Startkit to program away. We have done this also with success.

Be sure to post your schematic before starting the PCB layout to catch any possible issues. A key one being the in-rush current protection on the USB port. Also power supply sequencing.

We did a lot of experimenting a while ago and found Spansion to be very stable - now under the Cypress name. What you will need to do is to compare the SPI and QSPI commands between what XMOS recommends and what you will actually use. Summary, almost any flash on the market should work. The XFLASH tool can be modded to throw out custom commands like scripting but we found our dedicated code to be faster.

Lots of info to digest.
THANKS!