package BACK

import chisel3._
import chisel3.util._

import org.chipsalliance.cde.config._
import freechips.rocketchip.diplomacy._
import freechips.rocketchip.tilelink._


class SimpleSRAM()(implicit p: Parameters) extends BackModule{
  class SimpleSRAMIO extends Bundle{
    val mem = Flipped(new Mem_Port_Bundle)
  }

  val io: SimpleSRAMIO = IO(new SimpleSRAMIO)

  val mem = SyncReadMem(1024, UInt(32.W))


  io.mem.rdata := DontCare

  when( io.mem.valid & io.mem.wstrb.extract(0) ){
    mem.write( io.mem.addr(11,2), io.mem.wdata )

    assert( io.mem.wstrb.extract(1) & io.mem.wstrb.extract(2) & io.mem.wstrb.extract(3) )
  }

  io.mem.rdata := mem.read(io.mem.addr(11,2), true.B)

  val isReadAck = RegInit(false.B)
  when( io.mem.fire ){
    isReadAck := false.B
  } .elsewhen( io.mem.valid & io.mem.wstrb === 0.U ){
    isReadAck := true.B
  }

  io.mem.ready := 
    ( io.mem.wstrb =/= 0.U & true.B    ) |
    ( io.mem.wstrb === 0.U & isReadAck )

}