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Two types of PCB routing strategies

Different types of single boards have different wiring strategies. This article mainly introduces two types of печатная плата wiring strategies.

Стратегия компоновки печатной платы первого типа

1) The main features of Type 1 are as follows: strict length rules, strict crosstalk rules, topology rules, differential rules, power ground rules, etc.

2) Processing of key networks: bus

ipcb

Определить класс;

Требуется соответствие определенной топологической структуре, шлейфу и его длине (во временной области);

Two types of PCB routing strategies

Diagram of balanced daisy chain and intermediate drive daisy chain

Set virtual pins to control the topology;

Two types of PCB routing strategies

Virtual T point diagram

Limit STUB. Set the maximum stub length, the delay/length should be given a range; it is forbidden to go out from the long side of the pad; it is allowed to have a junction on the terminal.

3) Processing of critical network: clock line

Define Class, set sufficient line spacing or the spacing between Class and Class;

Set the clock line in a specific layer and area.

4) Обработка ключевой сети: дифференциальная линия

Generally need to specify the wiring layer;

Use parallel mode, avoid tandem mode;

Define the length matching of the two differential lines and the length matching of the differential pairs;

The usual way to set the spacing between differential line pairs is to define the differential pair as a class, and then define the spacing between Class to class.

5) Crosstalk control

Между сетевыми группами должен быть достаточный зазор; например, должны быть ограничения расстояния между линиями данных, адресными линиями и линиями управления, установите эти сети на соответствующий класс, а затем между линией данных и адресной линией, линией данных и линией управления Установите правила управления перекрестными помехами между линии, между адресными строками и линиями управления.

6) Shield

Shielding methods: parallel (parallel), coaxial (coaxial), cascade (tandem);

After the rules are set, you can use manual or automatic wiring.

Two types of PCB routing strategies

Стратегия компоновки печатной платы типа 2

1) Type 2 PCB design has both physical realization challenges and electrical rules realization challenges.

2) “Guide” is required during the wiring process, such as: Fanout, layer division, automatic wiring process control, forbidden area definition, wiring sequence, etc., need to be properly interfered.

3) Test and analyze the feasibility of wiring;

4) Consider the realization of physical rules first, and then the realization of electrical rules;

5) For conflicts or errors, it is required to comprehensively analyze the causes and adjust the wiring strategy in a targeted manner.

For PCB engineers, PCB wiring strategy is essential knowledge, and everyone should be proficient in it.