LAPTOP MOTHERBOARD SYSTEM SWITCHING

LAPTOP MOTHERBOARD SYSTEM SWITCHING

Laptop requirements in order to switch on first are the availability of 3V and 5VALW. Careful when finding 5VALW missing , switched on first cause of several motherboard, 5VALW appear after switch on .Than 3V_ALW or 3VPCU provide power supply to the EC , BIOS IC , South Bridge ( SB ) , clock generator and oscillator on ALW voltage .
VSB or switch voltage button (3.3V) will appear after Bios and EC powered. some of laptop motherboard will found 17V switch voltage on one of pin switch button but after switch -on voltage is changed to be 3.3 V. This is normal. Press power button ( short to ground ) then 3.3VSB will turn into 0V and back to 3.3V.and if standby VSB 17V press power button VSB become 0V and back to 3.3V. than power button is a good sign . steps further is the signal being sent to the EC ( Embedded controller NPCE 885LAODX ) signal names is NBSWON # most other brands of EC signal name may SW_ON, EC_ON or whatever name of the signal as long as signal coming from SW1 sent to EC , this voltage must respond in the same manner of testing power button , BIOS IC and firmware connected to SPI interface to the EC .Signal confirmation to ensure EC BIOS working properly is RSMRST # for3.3V.RSMRST# signal sometimes appear after switch on and other motherboard without switch on 3.3 V already present .Modern Motherboard has 2 or 3 IC BIOS. Identified EC BIOS which is usually one-page schema with EC names EC BIOS.
Other important signal from EC is DNBSWON # ,this is PWR_BTN signal to switch on South bridge sent by the EC after receiving NBSWON # signal from power button . DNBSWON # 3.3V must be present otherwise it would not switch on , after this signal appears then the SB will sent SUSCLK # signal back to the EC and turn on VS as trigger for all switching gate driver as VR_ON , Suson , MAINON , S5_ON or SLP_S3 , SLP_S4 and SLP_S5 . and for all the Vs voltage to the Device .

How switching system work on Laptop motherboard :

Laptop requirements in order to switch on first are the availability of 3V and 5VALW. Careful when finding 5VALW missing , switched on first cause of several motherboard, 5VALW appear after switch on .Than 3V_ALW or 3VPCU provide power supply to the EC , BIOS IC , South Bridge ( SB ) , clock generator and oscylator on ALW voltage .
VSB or swuitch voltage button (3.3V) will appear after Bios and EC powered. some of laptop motherboard will found 17V switch voltage on one of pin switch button but after switch -on voltage is changed to be 3.3 V.This is normal. Press power button ( short to ground ) then 3.3VSB will turn into 0V and back to 3.3V.and if standby VSB 17V press power button VSB become 0V and back to 3.3V. than power button is a good sign . steps further is the signal being sent to the EC ( Embedded controller NPCE 885LAODX ) signal names is NBSWON # most other brands of EC signal name may SW_ON, EC_ON or whatever name of the signal as long as signal coming from SW1 sent to EC , this voltage must respond in the same manner of testing power button , BIOS IC and firmware connected to SPI interface to the EC .Signal confirmation to ensure EC BIOS working properly is RSMRST # for3.3V.RSMRST# signal sometimes appear after switch on and other motherboard without switch on 3.3 V already present .Modern Motherboard has 2 or 3 IC BIOS. Identified EC BIOS which is usually one-page schema with EC names EC BIOS.
Other important signal from EC is DNBSWON # ,this is PWR_BTN signal to switch on South bridge sent by the EC after receiving NBSWON # signal from power button . DNBSWON # 3.3V must be present otherwise it would not switch on , after this signal appears then the SB will sent SUSCLK # signal back to the EC and turn on VS as trigger for all switching gate driver as VR_ON , Suson , MAINON , S5_ON or SLP_S3 , SLP_S4 and SLP_S5 . and for all the Vs voltage to the Device .

How switching signal work with EC and Southbridge and measuring point to get know if there are missing voltage and enable signal :

VS voltage magnitudes can be seen in the schema motherboard in question (VS voltage rail).

VS for Strap Boot device:
1.Procesor (VCCORE) rail voltage 0.9 V-1.5V
2.Ram (VCCRAM) Voltage 1.8V rail for DDR2, DDR3 VTT 1.5 V to 08V-0, 99V
3.Vga chips and input / output control, hub chip (VCCP) 1.5v rail voltage, 1.8 V, 3v

VS to Device (Lcd / led, hdd, optical, usb, wifi, bloutooth, keyboard, sound, camera etc.) For details on each Rail Voltage VS can be seen in the schema and Datasheet motherboard and components as well as the device in question.

Signal the wave triger / Sensor / 2-way confirmation signal / data interface
signal function open / close gate charge of organizing stages enable / disable each component or PCI (Peripheral commucition interface). Microcontroller System signal is governed by where the manufacturer has made a firmware binary command to set logic gate interface and low count pin into each IC bios on each motherboard.
Differences sircuit and arrangement on the motherboard of course require different settings Microcontroller, so that each of each different motherboard brand and series firmaware will necessarily require different settings.
This system can accept input signal, process it and deliver the output signal in accordance with the program in the contents into it.Microcontroller input signal derived from the sensor information from the environment (discrete) while the output signal addressed to the actuator (an electronic circuit for moving or controlling a mechanism or system) then give effect to the environment.
The microcontroller can easily analogized as the brain of a device / product that is programmed to be able to interact with the surrounding environment, embedded system is often referred to as the control systems that are embedded in a product.
Embedded System can not stand Alone
Microcontroller need to trigger the CPU clock oscillator working on one instruction to the next instruction in microcontroller operation time of one or several clock cycles to run.

There are several types of memory found in the microcontroller, ROM (ReadOnly Memory) and RAM (Random Access Memory). ROM is used as storage firmware while in modern electronic circuit use type EPROM (Erasable Programmable Read Only Memory) and EEPROM (Electrical Erasable Programmable Read Only Memory). CPU, memory, clock oscillator, and I / O are in one integrated circuit. If some elements omitted, then the system can not work.

Unlike the simple Embedded controller, microcontroller on sircuit LaptopMotherboard more complex embedded systems which have an external rom called the BIOS IC separate even they actually are part inseparable.