In-depth analysis of the notebook Structure

 

In-depth analysis of the notebook Structure

The application of computer technology has brought tremendous changes to our lives and work, which has led to a qualitative change in our life, study, and work. General users' understanding of computers generally stays at the application stage. They all develop and research applications based on computers. How much do we know about the computer's internal circuits? At present, there are very few documents and books about the computer's internal circuits, and there is little or no introduction to the laptop. Next we will introduce the circuit principle structure of the laptop. If you want to learn more about the circuit, please pay attention to the website www.SS5CN.net in this book.
1. circuit diagram of the laptop
As shown in the figure of the laptop, there are five parts as a whole.

(1) The CPU core is connected to the CPU temperature control circuit, the CPU core voltage supply circuit, and the CPU cooling fan control circuit.
(2) The memory controller is used as the core to connect the memory, video card, CPU, and I/O.
(3) the I/O controller is used as the core to connect the control circuit and interface circuit of the IDE (optical drive and hard drive), USB, Nic, sound card, PCI bus, and docking station.
(4) using the LPC bus as the core, they are connected to the SiO2 (Super Input and Output Controller), SMC/KBC (system management controller/keyboard controller), and FWH (firmware hub ), the SiO2 also includes the control circuit of serial port, parallel port, infrared and soft drive. SMC/KBC also includes the control circuit and system management controller for the keyboard and mouse.
(5) power supply circuit and battery charging circuit.

2. Laptop motherboard unit circuit Overview
2.1. Next we will give a brief introduction to the complete circuit structure supporting Intel's 855GM chipset in China.
The Pentium M processor CPU is the brain of a computer and the commander. It manages and controls other components for data transmission and processing.
The Pentium M processor is a dedicated Intel CPU designed for laptops. It operates in low-frequency, low-voltage, and multiple energy-saving modes, achieving high power-saving levels and good performance. It has the following features:
1. 32 KB Level 1 cache and 1 MB level 2 cache are integrated in the chip;
2. Supports SSE2 instruction sets;
3. supports enhanced SpeedStep technology to adjust the core voltage and frequency;
4. 4 MHz CPU bus frequency.
Pentium M leads to the CPU bus, also known as the Front-End bus, connected to the North Bridge chipset. The frequency is 400 MHz, which is actually achieved by sampling four times in a MHz clock period. The CPU bus signal uses the AGTL + logic, which is an electrical feature of the signal. It can improve the signal quality and reduce power consumption.
2.2 IMVP-IV core Voltage Control
IMVP-IV is a core Power Supply Circuit for the CPU, because the Pentium M core voltage adjustable (there are 32), so there must be a circuit that can accurately adjust the voltage. In addition, the CPU has some power management signals, also responsible for the IMVP-IV. It helps computers implement the SpeedStep technology.

3. Temperature Sensor
Place a temperature measuring diode under the CPU and connect it to the corresponding CPU pin. The circuit inside the CPU can detect its own temperature and provide protection for the high temperature once it occurs. The temperature measuring diode is also often provided to other control chips, such as ADM1023, to achieve temperature monitoring and complete certain system control, such as fan start.
4 Intel 855GM GMCH
The graphic Memory control Hub (Graphics & Memory Controller Hub, GMCH), also known as beiqiao. It is integrated with a graphics controller (display card) and a memory controller. It is provided with corresponding interfaces to connect the display device and memory. It also connects the Pentium M processor with ICH4, which is equivalent to the CPU manager, distribute CPU commands to the corresponding modules, or notify the modules of CPU requests when appropriate. It is also like the hub used in the network to achieve a one-point and multi-point connection.
855 the graphic memory control hub has three versions: 855GM, 855GME and 855PM. Among them, 855GME is an enhanced version of 855GM, and their PINs are compatible. 855PM is no longer called GMCH, but MCH, memory control hub. It is not integrated with a display card or corresponding display output, and is not compatible with 855GM/GME pins.
5. memory interface and DDR memory
The 855GM supports the memory interfaces of PC1600 and PC2100 ddr sdram. It can be inserted with DDR200/266 memory, and supports a maximum of GB memory. 855GME and 855PM also support PC2700 ddr sdram, namely DDR333 memory.
The notebook circuit provides SO-DIMM memory slots, which are small slots different from desktop memory slots, although signal standards are similar.
In the actual circuit, many laptops integrate memory on the motherboard to save space.
6 LVDS interface and LCD Control

LVDS is a low voltage differential signal specially used for LCD control signals. The control signal of the LCD is divided into two parts: scanning the dot matrix signal and controlling the brightness of the backlight.
7 Intel 82801DBM ICH4-M (I/O controller)
Input/Output Control Hub (I/O Controller Hub 4 Mobile, ICH4-M), 4 stands for the fourth generation, which provides powerful data I/O support for the system. It provides interfaces and corresponding peripheral devices: PCI bus, IDE devices (optical drive and hard drive), sound card, Nic, and USB.

8. IDE interfaces and IDE Devices
The ICH4-M provides two independent IDE signal channels, each supporting two IDE devices, with 16 Mb/s pio ide transmission or Ultra ATA 100/66/33 transmission, each IDE device has an independent clock. IDE devices are hard drives and optical drives.
Nowadays, an IDE interface technology named Serial ATA (Serial ATA) is emerging. It features a high transmission rate (150 Mb/s now) and a small number of transmission lines, intel's ICH5 already supports this technology, but it is currently only used for desktops. In fact, SATA is very suitable for laptops. I believe it will be transplanted to laptops soon.
9 USB Interface
ICH4 supports six USB ports, and these six ports can work in high-speed, full-speed, and low-speed modes respectively. ICH4 integrates two types of control to take charge of USB interfaces, UHCI controller and EHCI controller. UHCI Controller is responsible for full speed and low speed. EHCI Controller is responsible for high speed and up to 480 Mb/s. ICH4 automatically determines which controller controls a USB port.
10 PCI interface and PCI bus devices
ICH4 provides a 133MHz PCI interface to connect to the PCI bus. PCI bus is a widely used technology. Many boards and devices support this interface. on the desktop board, we can always find a white PCI expansion slot for inserting display cards, sound cards, and NICs. The notebook does not provide a PCI expansion slot to save space. Its PCI devices are usually directly deployed on the motherboard.
11 Docking
Docking is called a Docking slot to connect to the Docking device.
12 LPC interface and devices on the LPC Bus

Low Pin Count (LPC), which uses a small number of signal lines for Low-speed data transmission (33 Mb/s ). ICH4 directly provides an interface to bring out the LPC bus. Generally, the LPC bus is connected to devices such as FHW, SiO2, and KBC/SMC.
13 FWH
FWH is the full name of Firmware Hub, which is the Firmware Hub. When a maximum of 8 Mb system BIOS and a display BIOS system is enabled, the Firmware is first executed, complete system hardware resource testing and configuration? And enable the computer to load the operating system from the hard disk. In addition, it is also responsible for the basic input and output interfaces of the system hardware layer and the operating system throughout the system operation process.
14. SiO2
Super Input/Output (SIO) interfaces include serial port, parallel port, infrared interface, and soft drive interface. All these interfaces are connected to the LPC bus through PC87393 module groups, that is to say, PC87393 implements the signal conversion from the LPC to different I/O interfaces. Can it also be considered as a hub?
The signal lines of various I/O interfaces derived from PC87393 have been processed and connected to the plug-in, so that we can see and use them on the back or side of the laptop?

15 SMC/KBC
Different PS/2 (Keyboard/mouse Interface) interfaces with serial ports and parallel ports are not provided by PC87393, but are called System Management Controller (SMC) and Keyboard Controller (KBC ). From the perspective of name, it puts two irrelevant things together. Indeed, it provides two PS/2 interfaces to connect the keyboard and mouse, A keyboard scanning circuit is also provided directly to connect the built-in keyboard, which also implies that the built-in keyboard is not connected to the motherboard through the PS/2 port?
SMC/KBC is completed by Hitachi H8S/2149. It is a general-purpose microprocessor that can implement many functions through programming. This is why it integrates two unrelated functions.
16 LAN connector interface and LAN plug-in
This is different from the wireless network connection mentioned above, which is a wired connection. ICH4 provides the LAN Connection interface and LAN connector interface. The interface is connected to 82562EM and RJ45 plug-in is introduced for accessing the LAN. The 82562EM module only converts the LAN connector interface signal to the LAN online signal. It manages the network card controller and integrates it in ICH4.
17 sound card AC97
ICH4 supports the AC97 audio input and output standard, that is, the so-called soft sound card. It outputs Audio Information in a certain format and decodes this signal using the decoder (Codec, the Audio Information is restored, and the analog signal is converted into a analog signal through a digital-to-analog converter. After the amplifier is amplified, the audio can be output to the headphones and speakers for sound. Analog signals in telephone lines can also be considered as sound. Soft cats can be realized by connecting Modem Codec to the output line of AC97. In addition, AC97 supports audio input. Codec is responsible for encoding the input signal (after digital-analog conversion) to ICH4. ICH4 can be connected to a maximum of seven Codec channels to complete input and output of seven channels.
18 charging circuit
The charging circuit is a unique part of the laptop, which is used to manage the lithium-ion battery on the laptop to prevent the danger of battery overfilling.
19 DC/DC (DC distributor)
Converts the output DC voltage of the battery or the input voltage of the external power supply into the DC voltage of various levels and provides a certain load capability, providing power to each part of the circuit.
CK-408 20
A CK-408 is a clock synthesizer and driver that provides clock at different frequencies for many bus in the system, such as a MHz clock for the CPU Front-End bus and a 33 MHz clock for the PCI bus.