FPGA programming experience

Some important principles

1、 When modeling sequential circuits , Non blocking assignment

2、 Latch circuit modeling , Non blocking assignment

3、 use always When a block writes combinational logic , Assignment with blocking

4、 In the same always When both sequential and combinational logic circuits are established in the block , Non blocking assignment

5、 In the same always Do not use both non blocking and blocking assignments in blocks

6、 No more always Assign a value to the same variable in the block

# Follow the above principles , It is helpful to write integrable hardware correctly , And can eliminate 90%~100% Competitive risk phenomenon that may occur during simulation .

Timing error

Continuous use of combinatorial logic may lead to timing errors , This is because the data path is too long ,

resolvent ： Add registers on the long path for data buffering .

1、 High speed data processing uses less combinatorial logic , Because the data rate is too fast , Prone to competitive risk .

2、 High speed data stream processing , First cache ,

3、 For high-speed data processing , Try to use non blocking statements , Because of the use of continuous blocking statements, the data flow is fast , It will cause timing errors when it is actually implemented , Originally, what the blocking statement realizes is that the result becomes the same as that of the non blocking statement .

4、 You can't perform complex operations in one step .