Raspberry Pi 4

It reports the RT Preempt kernel...

Odd, I used the Gnipsel instructions and I get about 100 usec latency up to
maybe 200 if you run a browser/videos, How did you test latency?

I usually use
latency-histogram --nobase --sbinsize 1000

I just run latency test. Base thread is good, around 50,000.

PCW wrote:

The limitation is at 96 I/O maximum it could be very low for some specific applications, maybe we could find a way to reach 128 or 256 user I/O using some new FPGA like ARTIX 35K or 100K, or creating 2x HM2 firmware in a single FPGA if there is enough cells. it could be very easy and with a double SPI communication (SPI0 and SPI1) 2x96 = 192 I/O

Current IDROM format limits I/O to 144 pins not 96, raising this to 1024 or so would really only mean increasing the IDROM size and changing a few constants. This is independent of FPGA type.

Thanks
The 3x20 has 144 I/O you're right. I have a XC6SLX25 with 189 user I/O, i should try a 144 I/O config and maybe try more...
I have few pb with IDROMconst, maybe you could help me. I added this line to this file with a random number, but it's not working, my board is unreconized : github.com/youprint/Hostmot2SPI/blob/master/src/IDROMConst.vhd
i have to find the link into the linuxcnc source where the different boards are listed, maybe in rpspi.c

I know how it's work now.
I need to fork linuxcnc and add my board to rpspi.c and compile again linuxcnc (i made an image just before the linuxcnc compilation). If someone could tell me how to compile only the rpspi.c without recompile all linuxcnc, it could save me a lot of time.

COlger81 wrote: I just run latency test. Base thread is good, around 50,000.

Heres what I get with a servo thread only (about 4 hours):