问凿子在模块中保持值直到新的写入

EN

class MemristorCellBundle() extends Bundle {
    val writeBus = Input(UInt(1.W))
    val dataBus = Input(UInt(8.W))
    val cellBus = Output(UInt(8.W))
}

class MemCell() extends Module {
    val io = IO(new MemCellBundle())

    val write = Wire(UInt())
    write := io.voltageBus

    val internalValue = Reg(UInt())
    // More than 50% of total voltage in (255).
    when(write === 1.U) {
        internalValue := io.dataBus
        io.cellBus := io.dataBus
    } .otherwise {
        io.cellBus := internalValue
    }
}

class MemCellTest extends FlatSpec with ChiselScalatestTester with Matchers {
    behavior of "MemCell"
    it should "read and write" in {
        test(new MemCell()) { c =>
            c.io.dataBus.poke(5.U)
            c.io.write.poke(0.U)
            c.io.cellBus.expect(0.U)
            // Write
            c.io.dataBus.poke(5.U)
            c.io.write.poke(1.U)
            c.io.cellBus.expect(5.U)
            // Verify read-after-write
            c.io.dataBus.poke(12.U)
            c.io.write.poke(0.U)
            c.io.cellBus.expect(5.U)
        }
    }
}

test MemCell Success: 0 tests passed in 1 cycles in 0.035654 seconds 28.05 Hz
[info] MemCellTest:
[info] MemCell
[info] - should read and write *** FAILED ***
[info]   io_cellBus=0 (0x0) did not equal expected=5 (0x5) (lines in MyTest.scala: 10) (MyTest.scala:21)