Class: RubyHDL::High::Expression

Inherits:
Object
  • Object
show all
Defined in:
lib/HDLRuby/std/sequencer_sw.rb

Overview

Describes the software implementation of an expression.

Direct Known Subclasses

Binary, Ref, Ruby, Select, SignalI, Unary, Value

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(type) ⇒ Expression

Create a new expression with +type+ data type.


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# File 'lib/HDLRuby/std/sequencer_sw.rb', line 1545

def initialize(type)
  @type = type.to_type
end

Instance Attribute Details

#type ⇒ Object (readonly)

Returns the value of attribute type.


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# File 'lib/HDLRuby/std/sequencer_sw.rb', line 1543

def type
  @type
end

Instance Method Details

#<=(right) ⇒ Object

The <= operator which can be either a transmit or a comparison. By default set to transmit, and converted to comparison if child of operator or condition of sif/swhile statements.


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# File 'lib/HDLRuby/std/sequencer_sw.rb', line 1594

def <=(right)
  return Transmit.new(self.to_expr,right.to_expr)
end

#[](typ, rng = nil) ⇒ Object

Creates an access to elements of range +rng+ of the signal, and set the type of elements as +typ+ if given.

NOTE: +rng+ can be a single expression in which case it is an index.


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# File 'lib/HDLRuby/std/sequencer_sw.rb', line 1609

def [](typ,rng=nil)
  # Treat the number of arguments
  rng, typ = typ, nil unless rng
  # Process the range.
  if rng.is_a?(::Range) then
    first = rng.first
    if (first.is_a?(::Integer)) then
      first = self.type.size+first if first < 0
    end
    last = rng.last
    if (last.is_a?(::Integer)) then
      last = self.type.size+last if last < 0
    end
    rng = first..last
  end
  if rng.is_a?(::Integer) && rng < 0 then
    rng = self.type.size+rng
  end
  if rng.respond_to?(:to_expr) then
    # Number range: convert it to an expression.
    rng = rng.to_expr
  end 
  if rng.is_a?(Expression) then
    # Index case
    if typ then
      return RefIndex.new(typ,self.to_expr,rng)
    else
      return RefIndex.new(self.type.base,self.to_expr,rng)
    end
  else
    # Range case, ensure it is made among expression.
    first = rng.first.to_expr
    last = rng.last.to_expr
    # And create the reference.
    if typ then
      return RefRange.new(typ,
                          self.to_expr,first..last)
    else
      return RefRange.new(self.type.slice(first..last),
                          self.to_expr,first..last)
    end
  end
end

#mux(*choices) ⇒ Object

Converts to a select operator using current expression as condition for one of the +choices+.

NOTE: +choices+ can either be a list of arguments or an array. If +choices+ has only two entries (and it is not a hash), +value+ will be converted to a boolean.


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# File 'lib/HDLRuby/std/sequencer_sw.rb', line 1659

def mux(*choices)
  # Process the choices.
  choices = choices.flatten(1) if choices.size == 1
  choices.map! { |choice| choice.to_expr }
  # Generate the select expression.
  return Select.new(choices[0].type,self.to_expr,*choices)
end

#sdownto(val, &ruby_block) ⇒ Object

HW downto iteration.


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# File 'lib/HDLRuby/std/sequencer_sw.rb', line 1688

def sdownto(val,&ruby_block)
  RubyHDL::High.top_sblock << 
  Siter.new(RubyHDL::High.top_sblock.sequencer,self,"downto",&ruby_block)
end

#seach(&ruby_block) ⇒ Object

HW iteration on each element.


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# File 'lib/HDLRuby/std/sequencer_sw.rb', line 1670

def seach(&ruby_block)
  RubyHDL::High.top_sblock << 
  Siter.new(RubyHDL::High.top_sblock.sequencer,self,"each",&ruby_block)
end

#stimes(&ruby_block) ⇒ Object

HW times iteration.


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# File 'lib/HDLRuby/std/sequencer_sw.rb', line 1676

def stimes(&ruby_block)
  RubyHDL::High.top_sblock << 
  Siter.new(RubyHDL::High.top_sblock.sequencer,self,"times",&ruby_block)
end

#supto(val, &ruby_block) ⇒ Object

HW upto iteration.


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# File 'lib/HDLRuby/std/sequencer_sw.rb', line 1682

def supto(val,&ruby_block)
  RubyHDL::High.top_sblock <<
  Siter.new(RubyHDL::High.top_sblock.sequencer,self,"upto",&ruby_block)
end

#to_expr ⇒ Object Also known as: to_ref

Converts to an expression.


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# File 'lib/HDLRuby/std/sequencer_sw.rb', line 1550

def to_expr
  self
end

#to_ruby ⇒ Object Also known as: to_ruby_left

Convert to ruby code.


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# File 'lib/HDLRuby/std/sequencer_sw.rb', line 1562

def to_ruby
  raise "to_ruby not defined for class: #{self.class}."
end

#to_value ⇒ Object

Compute the expression (convert it to a value).


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# File 'lib/HDLRuby/std/sequencer_sw.rb', line 1557

def to_value
  raise "to_value not defined here."
end