Occasional ContributorConnect inclk of PLL to output port of alt_inbuf
Hi,
I would like to connect crystal oscillator to a general IO pin(e.g. E1) and then use the alt_inbuf to convert the input clock to inclk of PLL.
Please see my verilog code followed.
I am experiencing the error message:
Error (176554): Can't place PLL "nios_core:nios_core_inst|nios_core_PLL_BF:pll_bf|nios_core_PLL_BF_altpll_gka2:sd1|pll7" -- I/O pin clk (port type INCLK of the PLL) is assigned to a location which is not connected to port type INCLK of any PLL on the device
the questions are:
1) can I use general IO as crystal oscillator input to PLL?
2) what is wrong with my code bellow?
3) is there any example code about how to use general IO as crystal oscaillator input to PLL?
io_primitives osciin(
.data_in (clk),
.data_out (clk_temp)
);
module io_primitives (data_in, data_out);
input wire data_in;
wire internal_sig;
output wire data_out;
alt_inbuf my_inbuf (.i(data_in), .o(internal_sig));
defparam my_inbuf.io_standard="3.3-V LVCMOS";
defparam my_inbuf.location = "IOBANK_1";
defparam my_inbuf.enable_bus_hold = "on";
defparam my_inbuf.weak_pull_up_resistor = "off";
assign data_out = internal_sig;
endmodule
