EC/Bios Interaction Laptop Repair Course

Embedded Controller/BIOS Training
(Complete Bible)
VIKAS DEOARSHI
CHIPTRONIKS
VD Intellisys Technologies Pvt. LTd

South Bridge
LPC Bus
EC
SPI ROM
(BIOS +EC)
Power sequence
Battery
charge/discharge
Thermal IC
(CPU, GPU..)
Internal KB
(KB matrix)
Touch Pad
External PS/2
Fan Control
Func. Key,
LID switch, LED
CIR
En/disable
other devices
6
各個chip power on 的順序
PS/2
SM Bus
PWM SM Bus

Power-on Reset Circuit
Power consumption
AP note
17

Because the ITE EC chip has built-in a “level detection” for
power-on reset circuit, user may remove the external reset
IC for “WRST#” signal in EC design. A recommended
application circuit for the “WRST#” signal (pin 14) of EC is
illustrated as follow
18
Vstby
D1
C1
1uF
WRST#
R1 100K
pin 14
IT85xx

19
Each input pin should be driven or pulled
Input floating causes leakage current and should be
prevented.
Pins can be pulled by an external pull resistor or internal
pull for a pin with programmable pull.
Vstby
IT851x
R1
R
GPI
NO INTERNAL PULL H/L NEED EXTERNAL PULL H/L

1.Each output-drain output pin should be pulled
If an output-drain output pin is not used and is not pulled by an external pull resistor or internal
pull for a pin with programmable pull, make it drive low by the firmware.
2.Each input pin which belongs to VSTBY power plane is connected or pulled up to VCC
power plane
Such cases may cause leakage current when VCC is not supplied and a diode (low forward
voltage) may be used to isolate leakage current from VSTBY to VCC.
For example, use diodes for KBRST# and GA20 if they are connected to VCC power
plane of South-Bridge.
20
THE SAME POWER PLANE IS MUST
R
GPIO
R
Vstby
IT851x
Vstby
INTERNAL PULL HIGH
EXTERNAL PULL HIGH
DIFFERENT POWER PLANE
R
Vstby
"GOOD"
IT851x R
INTERNAL PULL HIGH
VCC
EXTERNAL PULL HIGH
South Bridge/Other Devices
2 1
Schottky Diode("low" forward voltage)
(FOR REFERENCE ONLY)
GPIO
Note: Such as KBRST#, GA20, SCI#…..etc., use a diode to connect to VCC
power plane (South Bridge) to isolate leakage current.
Note: Not only above pins but also all GPIOs are necessary for consideration.
Note: Most pins of IT851x belong to Vstby power plane.

21
It may cause a leakage current path when VCC is shut down.
Refer to the above consideration.
Any pin which belongs to VSTBY power plane should not be
pulled to VCC in most cases.
DIFFERENT POWER PLANE
*WRONG*
GPIO
R
EXTERNAL PULL HIGH
Vstby
IT851x
VCC
R
INTERNAL PULL HIGH
Vstby is high voltage, VCC is low voltage, may cause leakage current from H to L

Disable unnecessary pull for a programmable pull pin
Flash standby mode
Prevent accessing Scratch RAM before entering power-saving mode
Use Doze mode rather than Idle mode
Use Sleep mode rather than Doze mode
Gate clock by module in EC domain
Power-down ADC/DAC analog circuit if it is unnecessary
22

SM bus clock and data pin : In the NB design for control battery function, use the
battery on will hot plug-in and plug-off, and in the case of EC and battery has power in
plug in / off instantly easy to have instant high voltage surge occurs, it may cause SM
bus clock & data occurs EOS (Electrical Over Stress) damage possible. Therefore
recommended that customers add instant high voltage surge absorption lines, to
prevent EOS damage may occur, we recommend the following line :
23
SMB_DAT
D3
Zener Diode
Zener Diode Breakdown
around 5.6V
D2
Zener Diode
SMB_CLK
D4
Varistor
C1
100P
SMB_DAT
D5
Varistor
The Varistor provides protection from ESD
and EFT in highspeed data-line and other
high frequency applications.
SMB_CLK
C2
100P

The specification of level detection for power-on reset is illustrated as follow;
24
VSTBY
VSTBY POR
3.3V
0V
3.3V
0V
Vt+=2.89V
500us
Vt-=2.65V 10us Vt-=2.65V 10us

Battery Charge & Discharge
EC
ITE8512
Charge
IC
Battery A
Battery B
Charge Enable
Charge Enable
Battery B Temp/Voltage/Current Signal
SM Bus B
Battery A Temp/Voltage/Current Signal
SM Bus A
EC 應用概述Page: 26

Battery Charge & Discharge
Battery Charging
When connected to AC power and battery charging begins
Event notification will be sent simultaneously charging
Windows change the battery Icon
When charging the battery indicator light is orange
Read the gas gauge data and determine fully charged flags
Determine the charging voltage, current, temperature
When the indicator is green the battery is fully charged
Will send notification when the battery is fully charged
Event Windows change the battery Icon
Command
Battery
Gas gauge
EC Windows
Data
Page: 27 EC 應用概述
Polling
Data/Event

 Battery Discharge
 When removing the AC power supply battery begins to discharge
 Discharge will also send Event notification Windows change the
battery Icon
 Discharge light goes out
 Read the gas gauge data
 Determine the charging voltage,current,temperature
 Discharge warning divided into three stages Low # 1, Low # 2,
Shutdown
 Low # 1 flashing orange lights, Alarm Tone (according to BIOS Setup)
 Low # 2 flashing orange lights, the system enters the suspend mode
 Shutdown below the critical power, the system
forced shutdown
EC 應用概述
Page: 28
Battery
Gas gauge
EC Windows
Command
Data
Polling
Data/Event

Fan Control
CPU
Thermal
IC
CPU
VGA
Thermal
IC
VGA
ITE 8512
DAC0
DAC1
DAC2
SMC1
SMD1
SMC2
SMD2
( R.P.M )
CPU Sense
SYS Sense
VGA Sense
Fan Control IC
CPU
SYS
VGA
CPU
FAN
SYS
FAN
VGA
FAN

Fan Control
 Start temperature (Start), stop temperature
(Stop), down-temperature (Throttle)
 Fan rotation
 CPU(VGA) Temperature ≧ start temperature
 Fan Stops
 CPU(VGA) Temperature ≦ stop temperature
EC 應用概述
Page: 30
Temperature ℃
Fan Duty
%

 Down
 CPU(VGA) Temperature ≧ down temperature
 CPU(VGA) Temperature ≦ down temperature -n, reply
CPU frequency, n ≧ 5 ℃
Page: 31 EC 應用概述
Temperature ℃
CPU Speed
n
Throttle Temperature
Resume Temperature

 Abnormal Temperature warning
 When the EC can not be properly read CPU (VGA)
will also flash Num Lock & Caps Lock & Scroll Lock
indicator temperature, Alarm and warning systems
directly off one minute after
 Fan unusual Warning
 When the fan can not rotate properly will also flash
Num Lock & Caps Lock indicator and Alarm
1 A ↓
Blink
1 A ↓
Blink

Hardware Components: burning tool

EC 應用概述
1. KBD connector is
Page: 34
recognized as an upper
or lower contact and
connect Flash Board and
M / B
2. EC Debug Port of watch
dog enable pin to ground
3. USB cable to connect
Flash Board and
computer
4. M / B connected to the
AC power supply

 Burning software installed:
EC_WinFlash_Setup_265.exe
VDIT Page: 36

Setup
Type
Load
燒入

 Click the Load icon, choose File Open
VDIT Page: 40

 Click on the arrow to start burning after burning
is complete, burn the information bar displays Auto
Flash OK! And display process time
VDIT Page: 41

 Debug Port is also known 80Debug Port
80Debug Board
VDIT Page: 42

 M / B side Connector
VDIT Page: 43

 Debug Port Pin
 80PORT_DET# : When this pin is connected Debug
Board for Low
 80CLK clock pin
 3IN1 data pin This pin also use as a watch dog
 Debug Port What to do ?
1. Can be used as the system POST (Power On Self
Test) the boot process debugging
2. EC can be used as the system to detect and debug
VDIT Page: 44

 When the system boots 80Debug Port
automatically display system boot process
From 00 to FF
 Each number has its representative meaning
For example 13 KBC initial failure, 38 DRAM failure, 49 VGA ...
Show post process information
VDIT Page: 45

 EC Detect and Debug system
 Link Debug Board required only after adjustment
 Use www key & email key
adjustments Index
 Use Fn + F1 & Fn + F2 to adjust
Index
 Index
 00 EC Version
 01 CPU Remote Temperature
 02 CPU Local Temperature
 03 VGA Remote Temperature
 04 VGA Local Temperature
First Show Index
After the Show

 Index
 05 CPU Fan Speed
 06 VGA Fan Speed
 07 SysFlag01 (Shutdown Flag1, AC Mode)
 Bit0 SUSC Signal
 Bit1 Power Switch
 Bit2 CPU Over Temperature
Bit3 Power on Fail
 Bit4 Reserved
 Bit5 Command 95h
 Bit6 S4 Suspend to Disk
Bit7 Reserved
Bit7 Bit0
0 0 0 0 0 0 0 1 01

 Index
 Bit0 SMB Fail
Bit1 Reserved
 Bit2 VGA Over Temperature
 Bit3 Reserved
Bit4 Reserved
 Bit5 Reserved
 Bit6 Reserved
 Bit7 Reserved

 Index
 Bit0 CIR Using the remote control off
Bit1 Reserved
 Bit2 Reserved
 Bit3 Reserved
Bit4 Reserved
 Bit5 Reserved
 Bit6 Reserved
 Bit7 Reserved
VDIT Page: 49

 ITE 8512 EC Use I / O 62h and 66h port as a
communication interface
 62h for data port, as data access channel
 66hfor command port, As a command, status control
channel
 Read Data
Bit7 Bit0
- - - - - - IBF OBF
 First by the command port (66h) under the control command: EC to wait for the end
IBE(Input Buffer Empty, test 66h port bit1)
 Then by the data port (62h) read data :EC to wait for the
end OBF(Output Buffer Full, test 66h port bit0)
VDIT Page: 50

 Write Data
 Under the Command Port control commands start with :
EC to wait for the end IBE (Input Buffer Empty)
 Then write data from the Data Port : EC to wait for the end
IBE (Input Buffer Empty)
 Since the EC is responsible for many of the
peripheral signals control and monitoring coupled
with processing speed problems between each
command speed is not too high, it is recommended
not less than 150ms
VDIT Page: 51

 Read Project Name
 Command 92h
wait IBE ;(Test 66h port bit1 whether 0)
out 66h,92h
Loop:
wait OBF ;(Test 66h port bit0 whether 1)
in al,62h
store al to buffer
if al != ‘$’ goto Loop
Project Name : TN120R
VDIT Page: 52

 Reads the EC
version
 Command 93h
wait IBE
out 66h,93h
Loop:
wait OBF
in al,62h
store al to buffer
if al != ‘$’ goto Loop
VDIT Page: 53

 Read CPU 、VGA 、FAN Duty
 Command 9Eh
wait IBE
out 66h,9Eh
wait IBE
out 62h,n ;(n=1-3, 1=CPU, 2=VGA1, 3=VGA2)
wait OBF
in al,62h ;(remote temperature)
wait OBF
in al,62h ;(local temperature)
wait OBF
in al,62h ;(fan duty=(al*100)/255)
CPU Remote
Temp. : 55 ℃
CPU Local
Temp. : 45 ℃
CPU Fan

 Use AP control settings CPU & VGA FAN
Duty
 Command 99h
wait IBE
out 66h,99h
wait IBE
out 62h,n ;(n=0-3, 0=all fan, 1=CPU, 2=VGA, 3=fan3)
wait IBE
out 62h,m ;(m=fan duty=00~FF)

 Recovery EC automatic control CPU & VGA
FAN Duty
 Command 99h
wait IBE
out 66h,99h
wait IBE
out 62h,0FFh ;(0FFh 為EC Auto Control)
wait IBE
out 62h,m ;(1=CPU, 2=VGA, 3=VGA2, 0FFh=all fan)
VDIT Page: 56

 Read battery capacity (unit: mAh)
 Command 80h, 82h, 83h
 Index 2Eh, 2Fh (2byte, Battery Remaining Capacity)
Wait IBE
Out 66h,82h ;(Burst Enable)
wait IBE
out 66h,80h ;(Read)
wait IBE
out 62h,2Eh
wait OBF
in CapacityLowByte, 62h
out 62h,2Fh
wait OBF
in CapacityHiByte, 62h
Wait IBE
Out 66h,83h ;(Burst Disable)
Battery Capacity :
2100 mAh

 Read battery charge (unit: %)
 Command 80h, 82h, 83h
 Index 38h (1 byte, Battery Relative State)
Wait IBE
Out 66h,82h ;(Burst Enable)
wait IBE
out 66h,80h ;(Read)
wait IBE
out 62h,38h
wait OBF
in BatRelative, 62h
Out 66h,83h ;(Burst Disable)
Battery Relative : 95
%

 Bright green battery is fully charged,cannot display 100%, because there
are
 Battery itseld ( Learning Incomplete or poor design)
 EC
 BIOS(ASL is part of the BIOS, enter the Windows control
by OS)
 Reboot does not show 100%
 EC to determine the battery's internal information
Terminal Charge Flag cause, has been canceled this
judgment (M720S models)
 From re-open chance to show 100% (most of the reason)
When the battery is fully charged EC will send Event to
BIOS (ASL), because there is no Notify Battery Information
BIOS to OS, caused only Notify Status
VDIT Page: 59

 EC & BIOS INTERACTION
60
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