errors · bitdewfpga bit, yosys (when yosys-slang is not installed)
design.sv:7: ERROR [hierarchical-name]: u_cnt.count is a hierarchical name (a signal inside another instance). yosys does not resolve it (it made a 1-bit wire with no driver, so the board would not do what the simulation showed); Vivado resolves hierarchical names (UG901 Ch.9 Table 20). Fix: bring that signal out through an output port of its module and connect it here.
design.sv:7: ERROR [hierarchical-name]: u_cnt.count is a hierarchical name (a signal inside another instance). yosys does not resolve it (it made a 1-bit wire with no driver, so the board would not do what the simulation showed); Vivado resolves hierarchical names (UG901 Ch.9 Table 20). Fix: bring that signal out through an output port of its module and connect it here. https://nosey-dewdrop.github.io/dewfpga/errors/hierarchical-name/Why does it happen?
yosys' own reader treats u_cnt.count as a new implicit wire. yosys-slang resolves it, so with the second reader installed this line does not print; it appears with second-reader-missing.
What is the fix?
Run dewfpga install for the second reader, or bring the signal out through a port:
counter u_cnt(.clk(clk), .count(count));