I am using an ALTIOBUF megafunction in my design. it works as a LVDS tx buf.
Its outputs(dataout and dataout_b) stay at z when being simulated.
in the generated file(lvds_tx_buf.v) devoe of cyclone_iii_obuf is connected to 0.
---------------------------------------------
cycloneiii_io_obuf obufa_0
(
.i(wire_obufa_i[0:0]),
.o(wire_obufa_o[0:0]),
.obar(wire_obufa_obar[0:0])
`ifdef FORMAL_VERIFICATION
`else
// synopsys translate_off
`endif
,
.oe(1'b1),
.seriesterminationcontrol({16{1'b0}})
`ifdef FORMAL_VERIFICATION
`else
// synopsys translate_on
`endif
// synopsys translate_off
,
.devoe(1'b0)
// synopsys translate_on
);
defparam
obufa_0.bus_hold = "false",
obufa_0.open_drain_output = "false",
obufa_0.lpm_type = "cycloneiii_io_obuf";
---------------------------------------------
In module cycloneiii_io_obuf in cycloneiii_atoms.v
---------------------------------------------
assign tmp1 = (devoe == 1'b1) ? tmp : 1'bz;
assign tmp1_bar = (devoe == 1'b1) ? tmp_bar : 1'bz;
pmos (o, tmp1, 'b0);
pmos (obar, tmp1_bar, 'b0);
---------------------------------------------
i don't know if i have explained the problem exactly.
how to solve the problem?
