functioning of lid or hall switch
Posted: Fri Sep 23, 2016 1:13 pm
lid/hall switch. ...
Do you know how laptop goes to stand buy mode when we close laptop screen.???
It is because of this lid switch...( It will be a magnetic , mechanical and opto coupler)
Which let the laptop know what is a status of laptop flap or cover .... and enters in sleep states to save power .
It depends upon the manufacture or designer... how to use this Hall Switch.
In some case lid switch will not affect switching process (where as only back light of led/LCD is turned off only) in some cases it effects the switching process. (It may b enter in any sleep state mostly slp3 state ...)
Lid out is an active low signal and activates when low. It must be high to turn on the board .
In normal conditions lid out will be high 3.3v, when top cover of laptop is closed, Lid switch or hall switch sends the lid_close#(low) signal to the i/o controller . Whenever there is a input a response to it is must, then I/O sends the ec_lid_out# signal to ich/pch. Where the internal resisters of ich/pch(which are used to monitor, the events occurring) resets And system enters to spl_s3 state . In newer kind of boards lid# for I/O is present but the output to this response may not b a hard coded signal as ec_lid_out#.
There is SCI (system control interrupt) is used between I/O controller and pch to create this event.
Do you know how laptop goes to stand buy mode when we close laptop screen.???
It is because of this lid switch...( It will be a magnetic , mechanical and opto coupler)
Which let the laptop know what is a status of laptop flap or cover .... and enters in sleep states to save power .
It depends upon the manufacture or designer... how to use this Hall Switch.
In some case lid switch will not affect switching process (where as only back light of led/LCD is turned off only) in some cases it effects the switching process. (It may b enter in any sleep state mostly slp3 state ...)
Lid out is an active low signal and activates when low. It must be high to turn on the board .
In normal conditions lid out will be high 3.3v, when top cover of laptop is closed, Lid switch or hall switch sends the lid_close#(low) signal to the i/o controller . Whenever there is a input a response to it is must, then I/O sends the ec_lid_out# signal to ich/pch. Where the internal resisters of ich/pch(which are used to monitor, the events occurring) resets And system enters to spl_s3 state . In newer kind of boards lid# for I/O is present but the output to this response may not b a hard coded signal as ec_lid_out#.
There is SCI (system control interrupt) is used between I/O controller and pch to create this event.