Connecting the dots:
-litex platform file
-```litex-boards/litex_boards/platforms/ulx3s.py
+litex platform file litex-boards/litex_boards/platforms/ulx3s.py
+```
("gpio", 0,
Subsignal("p", Pins("B11")),
Subsignal("n", Pins("C11")),
),
```
-ulx3s contstraints file
-```github.com/emard/ulx3s/blob/master/doc/constraints/ulx3s_v20.lpf#L341-342
+ulx3s contstraints file github.com/emard/ulx3s/blob/master/doc/constraints/ulx3s_v20.lpf#L341-342
+```
LOCATE COMP "gp[0]" SITE "B11"; # J1_5+ GP0 PCLK
LOCATE COMP "gn[0]" SITE "C11"; # J1_5- GN0 PCLK
LOCATE COMP "gp[1]" SITE "A10"; # J1_7+ GP1 PCLK
LOCATE COMP "gn[1]" SITE "A11"; # J1_7- GN1 PCLK
```
-```https://github.com/emard/ulx3s/blob/master/doc/schematics_v308.pdf
+ULX3S FPGA Schematic https://github.com/emard/ulx3s/blob/master/doc/schematics_v308.pdf
+```
J1 J2 PIN number 1-40 is for FEMALE 90° ANGLED header.
For MALE VERTICAL header, SWAP EVEN and ODD pin numbers.