Models

Versioning

Adding a version attribute is strongly encouraged since this will be how bugs and features will be tracked in the future.

Since this is such a common attribute all Origen models already have a version attribute and if this key is passed to a sub_block definition it will automatically be attached to the sub-block, even in the case where a custom class is used.

When instantiating an SoC model we can supply a version and this should then cascade down the hierarchy affecting what versions of the sub-modules get instantiated.

Let’s say that two different versions of our Eagle device exist, and in turn each one instantiated a different version of the NVM IP. We can model that like this:

# lib/soc/eagle_m352.rb
module SOC
  class EAGLE_M352
    include Origen::TopLevel

    def initialize(options={})
      case version
      when 0
        sub_block :nvm, class_name: "NVM_M682", version: 3
      when 1
        sub_block :nvm, class_name: "NVM_M682", version: 5
      else
        fail "The BOM for version #{version} has not been defined!"
      end
    end
  end
end

Note that we define an error condition if our application attempts to instantiate a version that we have not defined.

We then cascade this information down the tree, so our NVM module should also instantiate it’s components based on the required version:

# lib/nvm/nvm_m682.rb
module NVM
  class NVM_M682
    include Origen::Model

    def initialize(options={})
      case version
      when 3
        sub_block  :analog,        class_name: "ANALOG_T921", version: 11
        sub_blocks :memory,        class_name: "MEMORY_128_B954", instances: 4, version: 12
        sub_block  :state_machine, class_name: "CONTROL_D345", version: 20

      when 5
        sub_block  :analog,        class_name: "ANALOG_T921", version: 12
        sub_blocks :memory,        class_name: "MEMORY_128_B954", instances: 4, version: 12
        sub_block  :state_machine, class_name: "CONTROL_D345", version: 24

      else
        fail "The BOM for version #{version} has not been defined!"
      end
    end

  end
end

We can test this out in the console:

$dut = SOC::EAGLE_M352.new(version: 0)
$dut.nvm.state_machine.version   # => 20

$dut = SOC::EAGLE_M352.new(version: 1)
$dut.nvm.state_machine.version   # => 24