在进行FPGA图像处理时，如果使用System Generator构建模型，有时有些算法不能实现时可以考虑Mcode来实现，但是其实在SysGen中Mcode是很弱的，因此需要了解它的能力有多大，才能更好的操作。
The MCode block supports the following MATLAB language constructs:
• Assignment statements• Simple and compound if/else/elseif end statements
• switch statements
• Arithmetic expressions involving only addition and subtraction
• Addition
• Subtraction
• Multiplication
• Division by a power of two
2 Relational operators:
3 Logical operators:
4 MATLAB functions
Type conversion. The only supported data type is xfix, the Xilinx fixed-point type.
The xfix() type conversion function is used to convert to this type. The conversion
is done implicitly for integers but must be done explicitly for floating point constants.
All values must be scalar; arrays are not supported.
• Shift functions: xl_lsh() and xl_rsh()
• Slice function: xl_slice()
• Concatenate function: xl_concat()
• Reinterpret function: xl_force()
• Internal state variables: xl_state()
