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OLIMEX / iCE40HX1K-EVB

FPGA development board made with KiCAD
Apache License 2.0
102 stars 29 forks source link

SRAM programming using FT2232 & Icestorm's iceprog #11

Open regymm opened 3 years ago

regymm commented 3 years ago

Hi, I made a slightly modified version of the board without much changing(downloading circuit unchanged), and now I have some problems with SRAM programming: moving R9 to R19 doesn't work. I'm using a custom FT2232H downloader and iceprog tool. Flash programming works so I think my downloader and FPGA chip have no problem.

If I unmount both R9 and R19, and manually swapping MISO/MOSI of the FT2232H, SRAM programming will work. However, whenever the R19 is populated(SDI and SDO of the FPGA are shorted), programing will fail(DONE not high after run iceprog).

Any ideas about the problem? Thanks in advance.

regymm commented 3 years ago

I also compared my case with the description in iceprog tool, seems they didn't directly short the FPGA's two pins -- this is the only difference between their and my setup as far as I found.

DanKoloff commented 3 years ago

So the unmodified version programs fine but the slightly modified version doesn't program. I'd suggest describing what exactly you modified and start from there.

regymm commented 3 years ago

Thanks for your reply. My modification is in the fork, with only an FT2232H downloader(this one) interface added, which gives the 5V power. The soldering is the same as schematics except the D2 diode is shorted according to this tweet.