Datasheet

OUT

DM_IN High

System in Sleep

CTL1 = 1 within 64ms of

sys wake, TPS2543 stays

in SDP/CDP and mouse

connection is maintained

CTL1 = 0 TPS2543

detects mouse and

ignores going to DCP

Mouse Clicked here

system wakes

2 V/div

OUT

1 V/div

CTL1

1 V/div

DM_IN

TPS2543

www.ti.com

SLVSBA6 –FEBRUARY 2012

Mouse/Key Board Wake Function

The TPS2543 supports low speed HID (human interface device like mouse/key board) wake function. It does not

support Full Speed HID. There are two scenarios under which wake on mouse is supported by the TPS2543.

They are:

1. CDP/SDP2 (111X) to DCP/Auto (011X)

2. SDP1 (010X) to DCP/Auto (011X)

Below description illustrates wake on mouse operation for scenario 1, same holds true for scenario 2.

When a low speed compliant device is attached to the TPS2543, charging port D- line will be pulled high in its

idle state (mouse/keyboard not activated). TPS2543 will monitor D- data line continuously. When device is in

CDP (1111) or SDP2 (1110) or SDP1 (010X) mode and system is commanded to go to sleep state, the device

CTL setting is also changed. Assuming it is changed to DCP/Auto, 011X, having previously detected a HID

attachment the device will simply ignore the command to go to DCP/Auto mode and stay in CDP/SDP2 state to

support wake on mouse function. When the USB low speed HID is activated (clicked) while system is in S3

(sleep) mode the high speed switch within the TPS2543 allows the transfer of signal from the HID device to the

USB host. The USB host subsequently wakes the system and changes CTL setting of the TPS2543 back to

CDP/SDP2 mode. Activating (clicking) the low speed device makes the D- data line go back low momentarily,

this triggers an internal timer within the TPS2543 to count down. If after ~64ms the CTL lines are still set at 011X

(DCP/Auto) the device will immediately switch to DCP/Auto mode and disconnect the mouse from the host. To

prevent this, the CTL setting must be made in less then 64 ms after HID device activation otherwise mouse/KB

function will be lost. See Figure 32 scope plot for an event sequence where mouse connection is maintained at

wake.

Mouse Wake from Sleep

Figure 32. Mouse Wake from Sleep Scope Plot

Product Folder Link(s): TPS2543