Class: HDLRuby::BitString
- Inherits:
-
Object
- Object
- HDLRuby::BitString
- Defined in:
- lib/HDLRuby/hruby_bstr.rb,
lib/HDLRuby/hruby_verilog.rb
Overview
Used to output bitstring. Enhance HDLRuby with generation of verilog code.
Constant Summary collapse
- B2S_T =
String conversion table.
[ "0", "1", "z", "x" ]
- TRUE =
A few common bit strings.
BitString.new("01")
- FALSE =
BitString.new("00")
- UNKNOWN =
BitString.new("xx")
- ZERO =
BitString.new("00")
- ONE =
BitString.new("01")
- TWO =
BitString.new("010")
- THREE =
BitString.new("011")
- MINUS_ONE =
BitString.new("11")
- MINUS_TWO =
BitString.new("10")
- MINUS_THREE =
BitString.new("101")
- NOT_T =
Not truth table NOT_T = { "0" => "1", "1" => "0", "z" => "x", "x" => "x" }
[ 1, 0, 3, 3 ]
- AND_T =
And truth table: 0, 1, 2=z, 3=x AND_T = { "0" => "1"=>"0", "z"=>"0", "x"=>"0", # 0 line "1" => "1"=>"1", "z"=>"x", "x"=>"x", # 1 line "z" => "1"=>"x", "z"=>"x", "x"=>"x", # z line "x" => "1"=>"x", "z"=>"x", "x"=>"x" } # x line
[ [ 0, 0, 0, 0 ], # 0 line [ 0, 1, 3, 3 ], # 1 line [ 0, 3, 3, 3 ], # z line [ 0, 3, 3, 3 ] ]
- OR_T =
Or truth table: 0, 1, 2=z, 3=x OR_T = { "0" => "1"=>"1", "z"=>"x", "x"=>"x", # 0 line "1" => "1"=>"1", "z"=>"1", "x"=>"1", # 1 line "z" => "1"=>"1", "z"=>"x", "x"=>"x", # z line "x" => "1"=>"1", "z"=>"x", "x"=>"x" } # x line
[ [ 0, 1, 3, 3 ], # 0 line [ 1, 1, 1, 1 ], # 1 line [ 3, 1, 3, 3 ], # z line [ 3, 1, 3, 3 ] ]
- XOR_T =
Xor truth table: 0, 1, 2=z, 3=x XOR_T = { "0" => "1"=>"1", "z"=>"x", "x"=>"x", # 0 line "1" => "1"=>"0", "z"=>"x", "x"=>"x", # 1 line "z" => "1"=>"x", "z"=>"x", "x"=>"x", # z line "x" => "1"=>"x", "z"=>"x", "x"=>"x" } # x line
[ [ 0, 1, 3, 3 ], # 0 line [ 1, 0, 3, 3 ], # 1 line [ 3, 3, 3, 3 ], # z line [ 3, 3, 3, 3 ] ]
- LOGIC_T =
[ AND_T, OR_T, XOR_T ]
Instance Method Summary collapse
-
#[](index) ⇒ Object
Gets a bit by +index+.
-
#[]=(index, value) ⇒ Object
Sets the bit at +index+ to +value+.
-
#clone ⇒ Object
Clone the bit string.
-
#each(&ruby_block) ⇒ Object
Iterates over the bits.
-
#initialize(val, opt = false) ⇒ BitString
constructor
Creates a new bit string from +val+.
-
#maybe_zero? ⇒ Boolean
Tells if the bit string could be zero.
-
#negative? ⇒ Boolean
Tells if the bit string is strictly negative.
-
#nonzero? ⇒ Boolean
Tells if the bit string is not zero.
-
#positive! ⇒ Object
Force the BitSting to be positive by appending a 0 is required.
-
#positive? ⇒ Boolean
Tells if the bit string is strictly.
-
#raw_content ⇒ Object
Give access to the raw content.
-
#reverse!(width) ⇒ Object
Reverse the content of the bit string assuming a bit width of +width+.
-
#reverse_each(&ruby_block) ⇒ Object
Reverse iterates over the bits.
-
#specified? ⇒ Boolean
Tell if the bit string is fully specified.
-
#to_i ⇒ Object
Convert the bit string to a Ruby Numeric.
-
#to_s ⇒ Object
(also: #str)
Converts to a string (sign bit is comprised).
-
#to_verilog ⇒ Object
Converts the system to Verilog code.
-
#trunc!(width) ⇒ Object
Truncs to +width+.
-
#zero? ⇒ Boolean
Tells if the bit string is zero.
Constructor Details
#initialize(val, opt = false) ⇒ BitString
Creates a new bit string from +val+. NOTE:* +val+ can be a Numeric or a String. * when +opt+ is :raw, val is considered to be the raw content.
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# File 'lib/HDLRuby/hruby_bstr.rb', line 47 def initialize(val, opt = false) # puts "val=#{val} val.class=#{val.class} opt=#{opt}" if opt == :raw then @content = [*val] elsif val.is_a?(Numeric) then # Content is a numeric. @content = [] if val > 0 then while val > 0 do @content << (val & 1) val /= 2 end @content << 0 else while val < -1 do @content << (val & 1) val /= 2 end @content << 1 end else # Content is not a numeric nor a BitString. @content = [] # Ensure it is a string. val = val.to_s.downcase val.each_byte.reverse_each do |c| case c when 48 # "0" @content << 0 when 49 # "1" @content << 1 when 120 # "x" @content << 3 when 122 # "z" @content << 2 else raise "Invalid bit: #{b.chr}" end end end end |
Instance Method Details
#[](index) ⇒ Object
Gets a bit by +index+. If +index+ is a range it is a range access.
NOTE: * Assumes index is a numeric or a range of numerics. * Access is compatible with Ruby array access and not with hardware access, e.g., 0..4 is not reversed. This is compatible with sub access of Numeric. * If the index is larger than the bit string width, returns the bit sign.
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# File 'lib/HDLRuby/hruby_bstr.rb', line 165 def [](index) if index.is_a?(Range) then # Process the left index. left = index.first left = left.to_i # Adjust left to @content size. left += @content.size if left < 0 left = left >= @content.size ? @content.size-1 : left # Process the right index. right = index.last right = right.to_i # Adjust right to @content size. right += @content.size if right < 0 right = right >= @content.size ? @content.size-1 : right # Do the access. if right >= left then # puts "left=#{left} right=#{right}" # Get the corresponding bits as a BitString return BitString.new(@content[left..right],:raw) else # Get the corresponding bits as a BitString return BitString.new(@content[right..left].reverse,:raw) end else # Process the index. index = index.to_i # Handle the negative index case. if index < 0 then return self[self.width+index] end # Process the index. index = index >= @content.size ? @content.size-1 : index b = @content[index] if b < 2 then # b is specified return it as an Numeric. return b else # b is not specified, create a new BitString. return BitString.new(b,:raw) end end end |
#[]=(index, value) ⇒ Object
Sets the bit at +index+ to +value+.
NOTE: * Assumes index is a numeric or a range of numerics. * Access is compatible with Ruby array access and not with hardware access, e.g., 0..4 is not reversed. This is compatible with sub access of Numeric. * when index is larger than the bit width, the bit string is X extended accordingly.
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# File 'lib/HDLRuby/hruby_bstr.rb', line 216 def []=(index,value) # Change inside the bit string, it is not know any longer if it # is specified or not @specified = nil # Process according to the kind of index. if index.is_a?(Range) then # Process the left index. left = index.first left = left.to_i # Adjust left and @content size. left += @content.size if left < 0 if left >= @content.size then # Overflow, sign extend the content. sign = @content[-1] @content.concat([sign] * (left-@content.size+1)) end # Process the right index. right = index.last right = right.to_i # Adjust right and @content size. right += @content.size if right < 0 if right >= @content.size then # Overflow, sign extend the bit string. sign = @content[-1] @content.concat([sign] * (right-@content.size+1)) end if right >= left then # puts "left=#{left} right=#{right} value=#{value} (#{value.class})" # Sets the value to a copy of the bit string. @content[left..right] = value.is_a?(BitString) ? value.raw_content[0..right-left] : (right-left+1).times.map do |i| value[i] end else # Sets the value to a copy of the bit string. @content[right..left] = value.is_a?(BitString) ? value.raw_content[left-right..0] : (left-right).down_to(0).map do |i| value[i] end end # puts "now @content=#{@content}" else # Process the index. index = index.to_i # Handle the negative index case. if index < 0 then return self[@content.size+index] = value end # Process the index. if index >= @content.size then # Overflow, sign extend the bit string. sign = @content[-1] @content.concat([sign] * (index-@content.size+1)) end # Sets the value to the bit string. @content[index] = value[0] end return value end |
#clone ⇒ Object
Clone the bit string.
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# File 'lib/HDLRuby/hruby_bstr.rb', line 90 def clone return BitString.new(@content,:raw) end |
#each(&ruby_block) ⇒ Object
Iterates over the bits.
NOTE: the sign bit in comprised.
Returns an enumerator if no ruby block is given.
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# File 'lib/HDLRuby/hruby_bstr.rb', line 343 def each(&ruby_block) # No ruby block? Return an enumerator. return to_enum(:each) unless ruby_block # A block? Apply it on each bit. @content.each(&ruby_block) end |
#maybe_zero? ⇒ Boolean
Tells if the bit string could be zero.
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# File 'lib/HDLRuby/hruby_bstr.rb', line 147 def maybe_zero? return ! self.nonzero? end |
#negative? ⇒ Boolean
Tells if the bit string is strictly negative.
NOTE: return false if the sign is undefined
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# File 'lib/HDLRuby/hruby_bstr.rb', line 130 def negative? return (@content[-1] == 1) end |
#nonzero? ⇒ Boolean
Tells if the bit string is not zero.
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# File 'lib/HDLRuby/hruby_bstr.rb', line 142 def nonzero? return @content.any? {|b| b == 1 } end |
#positive! ⇒ Object
Force the BitSting to be positive by appending a 0 is required.
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# File 'lib/HDLRuby/hruby_bstr.rb', line 122 def positive! @content << 0 if @content[-1] != 0 return self end |
#positive? ⇒ Boolean
Tells if the bit string is strictly.
NOTE: return false if the sign is undefined of if it is unknown if the result is zero or not.
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# File 'lib/HDLRuby/hruby_bstr.rb', line 117 def positive? return (@content[-1] == 0) end |
#raw_content ⇒ Object
Give access to the raw content. NOTE: the content is not copied, so there is a risk of side effect.
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# File 'lib/HDLRuby/hruby_bstr.rb', line 109 def raw_content return @content end |
#reverse!(width) ⇒ Object
Reverse the content of the bit string assuming a bit width of +width+.
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# File 'lib/HDLRuby/hruby_bstr.rb', line 96 def reverse!(width) # Ensure content is large enough. if @content.size < width then @content.concat(content[-1]*(width-@content.size)) else @content.trunc!(width) end @content.reverse! end |
#reverse_each(&ruby_block) ⇒ Object
Reverse iterates over the bits.
NOTE: the sign bit in comprised.
Returns an enumerator if no ruby block is given.
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# File 'lib/HDLRuby/hruby_bstr.rb', line 355 def reverse_each(&ruby_block) # No ruby block? Return an enumerator. return to_enum(:reverse_each) unless ruby_block # A block? Apply it on each bit. @content.reverse_each(&ruby_block) end |
#specified? ⇒ Boolean
Tell if the bit string is fully specified
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# File 'lib/HDLRuby/hruby_bstr.rb', line 399 def specified? @specified = ! @content.any? {|b| b > 1 } if @specified == nil return @specified end |
#to_i ⇒ Object
Convert the bit string to a Ruby Numeric.
NOTE: the result will be wrong is the bit string is unspecified. def to_numeric
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# File 'lib/HDLRuby/hruby_bstr.rb', line 389 def to_i # Compute the 2-complement's value. res = 0 @content.reverse_each { |b| res = res * 2 | b } # Fix the sign. res = -((1 << @content.size) - res) if @content[-1] == 1 return res end |
#to_s ⇒ Object Also known as: str
Converts to a string (sign bit is comprised).
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# File 'lib/HDLRuby/hruby_bstr.rb', line 152 def to_s return @content.reverse_each.map { |b| B2S_T[b] }.join end |
#to_verilog ⇒ Object
Converts the system to Verilog code.
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# File 'lib/HDLRuby/hruby_verilog.rb', line 1514 def to_verilog return "#{self.to_s}" end |
#trunc!(width) ⇒ Object
Truncs to +width+.
NOTE:
- trunc remove the end of the bit string.
- if the width is already smaller or equal than +width+, do nothing.
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# File 'lib/HDLRuby/hruby_bstr.rb', line 283 def trunc!(width) return self if width >= @content.size @content.pop(width-@content.size) end |
#zero? ⇒ Boolean
Tells if the bit string is zero.
NOTE: return false if the bit string is undefined.
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# File 'lib/HDLRuby/hruby_bstr.rb', line 137 def zero? return ! @content.any? {|b| b != 0 } end |