/**************************************************************************************
* Copyright (c) 2020 Institute of Computing Technology, CAS
* Copyright (c) 2020 University of Chinese Academy of Sciences
* 
* NutShell is licensed under Mulan PSL v2.
* You can use this software according to the terms and conditions of the Mulan PSL v2. 
* You may obtain a copy of Mulan PSL v2 at:
*             http://license.coscl.org.cn/MulanPSL2 
* 
* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, EITHER 
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, MERCHANTABILITY OR 
* FIT FOR A PARTICULAR PURPOSE.  
*
* See the Mulan PSL v2 for more details.  
***************************************************************************************/

package utils

import chisel3._
import chisel3.util._

object HoldUnless {
  def apply[T <: Data](x: T, en: Bool): T = Mux(en, x, RegEnable(x, 0.U.asTypeOf(x), en))
}

object ReadAndHold {
  def apply[T <: Data](x: Mem[T], addr: UInt, en: Bool): T = HoldUnless(x.read(addr), en)
  def apply[T <: Data](x: SyncReadMem[T], addr: UInt, en: Bool): T = HoldUnless(x.read(addr, en), RegNext(en))
}
