If DDS_DW is equal to DDS_D_DW there is no signal truncation and
consequentially no rounding should be performed. But the check whether
rounding should be performed currently is for if DDS_DW is less or equal to
DDS_D_DW.
When both are equal C_T_WIDTH is 0. This results in the expression
'{(C_T_WIDTH){dds_data_int[DDS_D_DW-1]}};' being a 0 width signal. This is
not legal Verilog, but both the Intel and Xilinx tools seem to accept it
nevertheless.
But the iverilog simulation tools generates the following error:
ad_dds_2.v:102: error: Concatenation repeat may not be zero in this context.
Xilinx Vivado also generates the following warning:
WARNING: [Synth 8-693] zero replication count - replication ignored [ad_dds_2.v:102]
Change the condition so that truncation is only performed when DDS_DW is
less than DDS_D_DW. This fixes both the error and the warning.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
- remove reset logic
- add wait for dac valid logic
- rewrite sine concatenation on wires for different path width to
suppress warnings
- use computed atan LUT tables
Lars-Peter Clausen
AndreiGrozav