1/*************************************************************************************** 2* Copyright (c) 2020-2021 Institute of Computing Technology, Chinese Academy of Sciences 3* 4* XiangShan is licensed under Mulan PSL v2. 5* You can use this software according to the terms and conditions of the Mulan PSL v2. 6* You may obtain a copy of Mulan PSL v2 at: 7* http://license.coscl.org.cn/MulanPSL2 8* 9* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, 10* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, 11* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE. 12* 13* See the Mulan PSL v2 for more details. 14***************************************************************************************/ 15 16package device 17 18import chisel3._ 19import chisel3.util._ 20import chipsalliance.rocketchip.config.Parameters 21import freechips.rocketchip.diplomacy.AddressSet 22import utils._ 23 24class KeyboardIO extends Bundle { 25 val ps2Clk = Input(Bool()) 26 val ps2Data = Input(Bool()) 27} 28 29// this Module is not tested 30class AXI4Keyboard 31( 32 address: Seq[AddressSet] 33)(implicit p: Parameters) 34 extends AXI4SlaveModule(address, executable = false, _extra = new KeyboardIO) 35{ 36 override lazy val module = new AXI4SlaveModuleImp[KeyboardIO](this){ 37 val buf = Reg(UInt(10.W)) 38 val ps2ClkLatch = RegNext(io.extra.get.ps2Clk) 39 val negedge = RegNext(ps2ClkLatch) && ~ps2ClkLatch 40 when (negedge) { buf := Cat(io.extra.get.ps2Data, buf(9,1)) } 41 42 val cnt = Counter(negedge, 10) 43 val queue = Module(new Queue(UInt(8.W), 8)) 44 queue.io.enq.valid := cnt._2 && !buf(0) && io.extra.get.ps2Data && buf(9,1).xorR 45 queue.io.enq.bits := buf(8,1) 46 queue.io.deq.ready := in.r.ready 47 48 in.r.bits.data := Mux(queue.io.deq.valid, queue.io.deq.bits, 0.U) 49 } 50 51} 52