(Since version chisel3, will be removed by end of 2017) use value.U
(Since version chisel3, will be removed by end of 2017) use value.U(width.W)
(Since version chisel3, will be removed by end of 2017) use value.U(width)
(Since version chisel3, will be removed by end of 2017) use n.U(width.W)
(Since version chisel3, will be removed by end of 2017) use n.U
(Since version chisel3, will be removed by end of 2017) use UInt(width)
(Since version chisel3, will be removed by end of 2017) use UInt(width.W)