How many have used the iCECube2 tool? I am just getting started with it and it seems to be less than optimal. It uses Synplify Pro for synthesis. I wrote code for a simple enabled up/down counter which I expect would use one LUT per bit. But it seems to be using two LUTs per. Instead of running the enable to the register, it is adding the enable into the logic to control whether the bit is inverted or not. This requires an extra input and so an extra LUT per bit. Here is the code involved.
... PORT ( SysRst : in std_logic; RateHigh : in std_logic; RateEn : in std_logic; ... signal VFOclkout : std_logic; signal PhaseStepReg : signed (RESOLUTION - 1 downto 0); ... PROCESS (VFOclkout, SysRst) begin if (SysRst ='1') then PhaseStepReg