Understanding Electronic Products and Motherboards - Embedded Hardware Design Basics (1)

1. Understand electronic products

Embedded electronic products, from the composition can be divided into hardware, software and structure.

Hardware is visible, electrical components, such as motherboards, displays, cameras and other electronic parts.

Software, that is, program code, is usually stored in a memory chip on the motherboard and runs on top of the motherboard. Hardware is the running carrier of software.

Structure, generally the shell of the product, the material can be plastic or metal. The role of the shell is roughly three, one is to let the hardware parts can be organically assembled together in accordance with the use of the product, the second is to protect the hardware parts, and the third is to make the product easy to use.

The following is a rough breakdown of the composition of embedded electronics:

2. Know the motherboard

For hardware engineers, the motherboard is the most important and critical object of work. The main daily work of hardware engineers is to design and debug the motherboard.

The motherboard is the core component of electronic products, and all functions achieved by the product are based on the motherboard. The motherboard is usually also electronic

The most complex parts of the product carry dozens to hundreds or even thousands of large and small electronic components on a PCB (Printed Circuit Board, printed circuit board). Such as CPU, Memory, storage (Flash), network chips, power chips, audio chips, IO chips, resistors, capacitors, inductors and connectors.

The composition of the motherboard can be broadly divided into two categories, one is PCB, and the other is electronic components.

PCB, Printed Circuit Board, translated into Chinese is "printed circuit board" or "printed circuit board". It is the carrier of all electronic components on the motherboard, and the metal wires on it make the electrical interconnection between the various components. Because it is produced by electronic printing, it is called a "printed" circuit board.

Electronic components, generally can be divided into IC (Integrated Circuit), separate components, modules (modules).

IC is what we often call an integrated circuit, commonly known as a chip. The transistors, resistors, capacitors, inductors and other components required in a circuit and the connections between each other are made on a small or several small pieces of semiconductor chips or dielectric substrates through relevant processes, and then packaged in a tube shell to become a miniature structure with the required circuit functions. The following is a few common IC physical picture.

SoC, System on Chip. Soc, system on chip. It is a highly integrated, very complex chip that integrates a CPU, GPU, VPU, memory controller, storage controller, display driver, and other peripheral controllers.

MCU, Micro Controller Unit. It is often referred to as the single chip microcomputer, which is the Central processing Unit (Central Process Unit; The frequency and specifications of CPU are appropriately reduced, and peripheral interfaces such as memory, counter (Timer), USB, A/D conversion, UART, PLC, DMA, and even LCD driver circuits are integrated on a single chip to form a chip-level computer. Generally weaker than SOCs in performance and less functional than SOCs.

DDR, Dynamic Double Rate, full name Dynamic Double Rate SDRAM, double speed dynamic random access memory, is a kind of memory.

eMMC, Embedded Multi Media Card, is an embedded memory for products such as mobile phones or tablets. Its function is similar to that of a hard disk to store data.

Audio Codec, audio COdec chip.

DCDC, DC to DC, direct flow DC. It is a DC power conversion chip that converts a DC voltage of one specification to a lower or higher DC voltage of another.

Separate components generally refer to single (or single-function) electronic components such as resistors, capacitors, inductors, and transistors. They are single-function and belong to the "smallest" components. The following is an example of several common separation components.

Module (Module, also known as module), it is in order to achieve certain functions and the PCB and a relatively small number of electronic components (IC and separated components) organic combination design together, a higher level than ordinary electronic components, more complex electronic components. If divided according to function, there are WiFI/Bluetooth communication modules, 4G/5G wireless communication modules, camera modules, etc., and even Smart modules with richer and more complex functions (Smart Module, which will be explained in more detail later). From the design point of view, the use of modules can reduce the design complexity and design threshold, reduce the probability of design errors, shorten the design development cycle. Below are several common modules.

Above, we talk about the composition of the motherboard, the main board of the three categories of components (PCB, electronic components, modules), let's take a look at some common embedded motherboard physical drawings, in order to have an intuitive impression of the motherboard.

We can see that these motherboards have SoC, Memory (DDR), storage (eMMC Flash), network chips, intelligent modules and functional modules, and separate components such as resistors, capacitors, and inductors.

Of course, a motherboard is not without functional interfaces, such as the USB interface, gigabit network port, headphone interface, HDMI interface in the picture of the above two motherboards. Only with these interfaces can the motherboard be easily operated, and the motherboard can also communicate with the outside world.