Abstract: A system provided for protecting a disk drive from impact damages. More specifically, a disk drive is provided that includes an accelerometer interconnected to a printed circuit board that detects free fall of the disk drive. In addition, the velocity of spinning disks of the disk drive is also monitored to assess changes in velocity thereof that may indicate the presence of a tumbling condition. Furthermore, the change in acceleration measured by the accelerometer is monitored to prevent false indications of free fall due to common vibrations. Thus an enhanced system is provided that protects disk drives from the effect of free falls under a wide variety of conditions and allowing for drops from shorter distances to be identified.

Abstract: An optical transceiver module is disclosed with improved digital diagnostic integrated circuits. The optical transceiver includes an electrical-to-optical transmitter and an optical-to-electrical receiver each coupled to a digital diagnostic integrated circuit. A bi-directional 2-wire control interface is provided and a microcontroller couples the digital diagnostic integrated circuit to the control interface. Various methods are described for using the microcontroller to incorporate changes or diagnostic functions in the digital diagnostic integrated circuit.