位宽不匹配(Width mismatch)

简介

SpinalHDL将检查赋值左侧和右侧的运算操作和信号具有相同的位宽。

赋值示例

下面的代码：

class TopLevel extends Component {
  val a = UInt(8 bits)
  val b = UInt(4 bits)
  b := a
}

会报错：

WIDTH MISMATCH on (toplevel/b :  UInt[4 bits]) := (toplevel/a :  UInt[8 bits]) at
  ***
  Source file location of the OR operator via the stack trace
  ***

一个可能的修复方法是：

class TopLevel extends Component {
  val a = UInt(8 bits)
  val b = UInt(4 bits)
  b := a.resized
}

运算操作示例

下面的代码：

class TopLevel extends Component {
  val a = UInt(8 bits)
  val b = UInt(4 bits)
  val result = a | b
}

会报错：

WIDTH MISMATCH on (UInt | UInt)[8 bits]
- Left  operand : (toplevel/a :  UInt[8 bits])
- Right operand : (toplevel/b :  UInt[4 bits])
  at
  ***
  Source file location of the OR operator via the stack trace
  ***

一个可能的修复方法是：

class TopLevel extends Component {
  val a = UInt(8 bits)
  val b = UInt(4 bits)
  val result = a | (b.resized)
}