private void writeDataPathMultiplexer(StreamWriter stream, Multiplexer.Multiplexer multiplexer)
{
stream.WriteLine();
stream.WriteLine($"\t-- {multiplexer.Name}: {string.Join(", ", multiplexer.ItemNames)}");
stream.WriteLine($"\t{multiplexer.Name} : c_multiplexer");
stream.WriteLine($"\t\tgeneric map({multiplexer.OutputBitSize}, {multiplexer.ItemCount}, {multiplexer.SelectionBitSize})");
stream.WriteLine("\t\tport map");
stream.WriteLine("\t\t(");
//wire up inputs
var inputBitIndex = 0;
foreach (var item in multiplexer.Items)
{
var register = item as RegisterBase;
if (register != null)
{
if (register is InputRegister)
{
stream.WriteLine($"\t\t\tinput({inputBitIndex + register.Bits - 1} downto {inputBitIndex}) => {register.Name}({register.Bits - 1} downto 0), -- {register.Name}");
inputBitIndex += register.Bits;
}
else
{
var operation = AifFile.Operations.Values.First(op => op.Output == register);
var operationUnit = Functional.Units.First(unit => unit.Operations.Contains(operation));
stream.WriteLine($"\t\t\tinput({inputBitIndex + register.Bits - 1} downto {inputBitIndex}) => {operationUnit.Name}_out({register.Bits - 1} downto 0), -- {register.Name}");
inputBitIndex += register.Bits;
}
}
else
{
var op = (Operation)item;
stream.WriteLine($"\t\t\t-- Operation {op.Name}: {op.Op}({op.Left.Name}, {op.Right.Name})");
inputBitIndex += writeDataPathMultiplexerRegister(stream, inputBitIndex, op.Left);
inputBitIndex += writeDataPathMultiplexerRegister(stream, inputBitIndex, op.Right);
}
}
//wire up selector
var controlIndex = GetControlIndex(multiplexer);
stream.Write("\t\t\tmux_select");
stream.WriteLine(multiplexer.SelectionBitSize == 1 ?
$"(0) => ctrl({controlIndex})," :
$"({multiplexer.SelectionBitSize - 1} downto 0) => ctrl({controlIndex} to {controlIndex + multiplexer.SelectionBitSize - 1}),");
//wire up the output
stream.WriteLine($"\t\t\toutput => {multiplexer.Name}_out");
stream.WriteLine("\t\t);");
}
private string writeControllerValueFor(StreamWriter stream, Multiplexer.Multiplexer multiplexer, int cycle, int index)
{
stream.Write("\t\t\t\tcontrol_bus(");
var value = multiplexer.GetSelectValueAndNameFrom(cycle);
stream.Write(value.Item1.Length == 1 ?
$"{index}) <= '{value.Item1}'" :
$"{index} to {index + value.Item1.Length - 1}) <= \"{value.Item1}\"");
stream.Write($"; -- {value.Item1} {multiplexer.Name}");
if (string.IsNullOrEmpty(value.Item2))
{
stream.WriteLine();
}
else
{
stream.WriteLine($": select {value.Item2}");
}
return(value.Item1);
}
protected int GetControlIndex(Multiplexer.Multiplexer multiplexer)
{
return(RegisterAllocator.Units.Length + Multiplexers.Multiplexers
.TakeWhile(item => item != multiplexer)
.Sum(item => item.SelectionBitSize));
}
