Introduction to Embedded Systems
Exercise 2 MOC-stateChartStatechart
- Advantages of StateCharts
What are the most important extensions of the StateChart model in
comparison to an ordinary Finite state machine (FSM)?
状态图可以对层次结构和并发进行建模。可以警戒（有条件地启用）转换。此外，转换可以与操作相关联。 操作可以与操作相关联。 操作可以对变量执行计算，并生成新事件。状态图(Statechart Diagram)是描述一个实体基于事件反应的动态行为，显示了该实体如何根据当前所处的状态对不同的事件做出反应。
- Disadvantages of StateCharts
What are the disadvantages of the StateChart formalism?
虽然StateChart比普通的FSM更好，但是它们在大型系统中的规模越来越大，往往很难理解。 重复使用的潜力是有限的。 与转换相关的操作提供了强大的扩展，但另一方面，广泛使用的操作将部分系统状态信息从状态本身移动到变量。 这种隐藏状态使系统分析困难。
- Tree of states for StateChart
Given the StateChart in Figure 1. Draw the state space of the StateChart
as a tree, which shows the hierarchy of states anddenotes the state types
(basic state, sequential states, and parallel states).
- Formal computation of state space
How would you formally compute the set of states? Compute the set of
states for the hierarchical automata which is defined bythe StateChart from
Fig.1
- Analysis
The automaton defined by the StateChart from Fig. 1 passes through a
number of states, when external events are applied.Show the sequence of
state that are passed through, starting from the initial state, for the
following sequence of events:
- Conversion of StateChart to a finite state machine (FSM)
Draw a finite state machine which is equivalent to the StateChart from
Fig. 1. Minimize the number of states.
- StateChart model of a vending machine
The StateChart model of a simplified vending machine is shown in Figure
2.
- Describe the trace of transitions occurring when the user inserts a coin and orders a tea.
-
The control of the vending machine has a bug that allows the user to cheat.
Describe the trace of transitions that illustratethe bug.
image.png Draw the corresponding StateChart that fixes the bug.
Bug：
Correct：
Simulated：
设置一个人想要喝咖啡的状态：
输入事件：
coin_in=1;
cancel=0;
drink_ready=1
req_tea=0;
req_coffee=0;
仿真结果为：
输出事件
start_coffee=1;
start_tea=0;
coin_out=0;
验证模型是正确的,输出为
