基于FPGA的图像处理（五）--状态机

╰半夏微凉° 2022-05-14 07:57 218阅读 0赞

使用FPGA实现各种算法时，状态机是很常用的方法，在SysGen中有两种非常简便的方法构建状态机，一是使用Mcode，以switch-case语句轻松实现，二是使用SysGen自带状态机模块。

状态机

假设我们要从01序列中检测出1011序列，则状态机模型如下

Next State Matrix：\[0 1; 2 1; 0 3; 2 1\]

Output Matrix ： \[0 0; 0 0; 0 0; 0 1\]

![1354197888_7134.jpg][]

一、使用Mcode实现

上一篇博客讲解了在Sysgen中Mcode的限制能力，这里直接使用

构建模型如下：

![1354198094_5997.jpg][]

Singal From Workspace用于产生一个01序列，作为输入信号。

gatwayIn将数据类型转化为UFix\_1\_0

添加Mcode函数stateMcode.m

function [nextState, matched] = stateMcode(currentState, din) % This is the update function for detecting a pattern of 1011 % This function represents a stateless and combination logic block. % The output nextState should be to a register, and the output % of the register should be fed back to the input currentState. % Because the state register block has a feed back connection, in % order to propagate the port prototypes automatically, the prototype % of nextState should be determined only by constants or through % an explicity xfix() call. seen_none = 0; % initial state, if input is 1, switch to seen_1 seen_1 = 1; % first 1 has been seen, if input is 0, switch % seen_10 seen_10 = 2; % 10 has been detected, if input is 1, switch to % seen_1011 seen_101 = 3; % now 101 is detected, is input is 1, 1011 is % detected and the FSM switches to seen_1 % the default value of matched is false matched = false; switch currentState case seen_none if din==1 nextState = seen_1; else nextState = seen_10; end case seen_1 % seen first 1 if din==1 nextState = seen_1; else nextState = seen_10; end case seen_10 % seen 10 if din==1 nextState = seen_101; else % no part of sequence seen, go to seen_none nextState = seen_none; end case seen_101 if din==1 nextState = seen_1; matched = true; else nextState = seen_10; matched = false; end otherwise % if nextState is not assigned outside the switch statement, % an otherwise statment is required nextState = seen_none; end

Scope效果如图：

![1354198308_9963.jpg][]

二、使用Mealy State Machine模块实现

构建模型：

![1354198386_4649.jpg][]

设置Mealy State Machine参数，就是状态机的参数

![1354198422_9080.jpg][]

仿真结果如下：

![1354198457_9289.jpg][]

在进行FPGA图像处理时，经常会用到状态机，这几天刚学习过，记录一下，其实使用Verilog直接实现也不是很难，只是会比SysGen稍微麻烦一些，修改起来也会花费更多的时间。

Model Based Design 在Xilinx 的工具中逐渐得到加强，相信以后会更加的方便。

[1354197888_7134.jpg]: https://img-my.csdn.net/uploads/201211/29/1354197888_7134.jpg
[1354198094_5997.jpg]: https://img-my.csdn.net/uploads/201211/29/1354198094_5997.jpg
[1354198308_9963.jpg]: https://img-my.csdn.net/uploads/201211/29/1354198308_9963.jpg
[1354198386_4649.jpg]: https://img-my.csdn.net/uploads/201211/29/1354198386_4649.jpg
[1354198422_9080.jpg]: https://img-my.csdn.net/uploads/201211/29/1354198422_9080.jpg
[1354198457_9289.jpg]: https://img-my.csdn.net/uploads/201211/29/1354198457_9289.jpg