19

USB COMMAND DETAILS

USB_RESET

USB Spec:

Notes:

D+/D- low for an extended period

A device may reset after seeing an SE0 for more than 18.7 uS, and definitely after 10 mS.

After power up and prior to Reset, the device will not respond to any USB commands. After the device

has been given a USB Reset, the device’s address will be reset to zero and the device will be in the

Default state. The chip will default to Report protocol and any pending output will be flushed.

All registers will be reset to a state that matches power-on-reset with the following exceptions: USB

State register will be “Default” instead of “Attached”.

USB_SUSPEND

USB Spec:

Notes:

Idle state for an extended period

A device may suspend after seeing an idle for more than 3 mS, and definitely after 10 mS.

The chip will take a minimum of 5 mS to start Suspend, though will definitely start after 6 mS. The chip

may finish the current frame if necessary before stopping the clock. Thus, an additional frame time may

be used to reach Suspend mode.

USB_RESUME

USB Spec:

Notes:

Non-idle state

Remote Resume signalling from a device must be between 1 mS and 15 mS. The host is required to

send Resume signaling for 20 mS plus 10 mS of resume recovery time in which it does not access any

devices. This allows devices enough time to wake back up.

The chip can cause a Resume if Remote Wakeup is enabled and a button has been pressed. Remote

resume signalling from the chip will last 11.45 mS to 12.45 mS.

Get_Status_Device

Returns:

Default:

Addressed:

Configured:

Notes:

80 00 00 00 00 00 02 00

xx yy

xx[0] = Self Powered

xx[1] = Remote Wakeup

xx[7:2] = 0

yy = 00 (Reserved)

Accept (undefined in USB Spec)

Accept

Accept

Use Set_Feature_Device/Clear_Feature_Device to set/clear remote wakeup.

Get_Status_Interface

Returns:

Default:

Addressed:

Configured:

Notes:

81 00 00 00 00 00 02 00

00 00

Stall (undefined in USB Spec)

Stall

Accept

Both return bytes are reserved and currently 00.

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PixArt Imaging Inc.

PixArt Imaging Inc.

ADNS-2710 Single Chip USB Optical Mouse Sensor