https://bugs.libre-soc.org/show_bug.cgi?id=517
http://lists.libre-soc.org/pipermail/libre-soc-dev/2020-October/000873.html
-```lkcl
+lkcl:
+```
the JTAG TAP interface on the *FPGA* is hard-coded silicon.
the JTAG TAP interface connected on the processor and soft-implemented
Connecting the dots:
-
litex platform file litex-boards/litex_boards/platforms/ulx3s.py
-```
+
("gpio", 0,
Subsignal("p", Pins("B11")),
Subsignal("n", Pins("C11")),
Subsignal("n", Pins("A11")),
IOStandard("LVCMOS33")
),
-```
-ulx3s contstraints file github.com/emard/ulx3s/blob/master/doc/constraints/ulx3s_v20.lpf#L341-342
-```
+ULX3S FPGA constraints 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
-```
ULX3S FPGA Schematic https://github.com/emard/ulx3s/blob/master/doc/schematics_v308.pdf