xref: /XiangShan/src/main/scala/device/AXI4UART.scala (revision bdc16061fa79a390b1b364b4281d86803a14fe54)
1/***************************************************************************************
2* Copyright (c) 2020-2021 Institute of Computing Technology, Chinese Academy of Sciences
3* Copyright (c) 2020-2021 Peng Cheng Laboratory
4*
5* XiangShan is licensed under Mulan PSL v2.
6* You can use this software according to the terms and conditions of the Mulan PSL v2.
7* You may obtain a copy of Mulan PSL v2 at:
8*          http://license.coscl.org.cn/MulanPSL2
9*
10* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
11* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
12* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
13*
14* See the Mulan PSL v2 for more details.
15***************************************************************************************/
16
17package device
18
19import chisel3._
20import chisel3.util._
21import org.chipsalliance.cde.config.Parameters
22import freechips.rocketchip.diplomacy.AddressSet
23import utils._
24import utility._
25import difftest._
26
27class AXI4UART
28(
29  address: Seq[AddressSet]
30)(implicit p: Parameters)
31  extends AXI4SlaveModule(address, executable = false, _extra = new UARTIO)
32{
33  override lazy val module = new AXI4SlaveModuleImp[UARTIO](this){
34    val rxfifo = RegInit(0.U(32.W))
35    val txfifo = Reg(UInt(32.W))
36    val stat = RegInit(0.U(32.W))
37    val ctrl = RegInit(0.U(32.W))
38
39    val txDataPos = (4 % node.portParams.head.beatBytes) * 8;
40
41    io.extra.get.out.valid := (waddr(3,0) === 4.U && in.w.fire)
42    io.extra.get.out.ch := in.w.bits.data(7 + txDataPos, txDataPos)
43    io.extra.get.in.valid := (raddr(3,0) === 0.U && in.r.fire)
44
45    val mapping = Map(
46      RegMap(0x0, io.extra.get.in.ch, RegMap.Unwritable),
47      RegMap(0x4, txfifo),
48      RegMap(0x8, stat),
49      RegMap(0xc, ctrl)
50    )
51
52    RegMap.generate(mapping, raddr(3,0), in.r.bits.data,
53      waddr(3,0), in.w.fire, in.w.bits.data, MaskExpand(in.w.bits.strb >> waddr(2,0))
54    )
55  }
56}
57