1 This is a small chunk of communication on the SCLK and SDIO pins of the
2 Avago ADNS-2051 optical mouse sensor.
5 http://www.avagotech.com/docs/AV02-1364EN (PDF)
6 http://www.avagotech.com/pages/en/navigation_interface_devices/navigation_sensors/led-based_sensors/adns-2051/