Activity indicator for mass storage device

An integrated circuit for providing an activity indicator for a mass storage device, the integrated circuit comprising:

• a first input for receiving enclosure management data from a host bus adapter;
• a second input for receiving a drive activity signal from a mass storage device, wherein the drive activity signal received on the second input is toggled when the mass storage device is active, and wherein determining from the drive activity signal received on the second input whether the mass storage device is active comprises determining whether the drive activity signal is being toggled;
• a first output for generating an indication that the mass storage device is active;
• and
• a processing portion operative to
• (a) decode the enclosure management data to determine whether the enclosure management data indicates that the mass storage device is active,
• (b) determining whether the decoded enclosure management data indicates that the mass storage device is active,
• (c) in response to determining that the decoded enclosure management data indicates that the mass storage device is active set a protocol variable to indicate that the decoded enclosure management data indicates that the mass storage device is active,
• (d) in response to determining that the decoded enclosure management data does not indicate that the mass storage device is active reset the protocol variable to indicate that the decoded enclosure management data does not indicate that the mass storage device is active,
• (e) upon resetting the protocol variable receive a drive activity signal from the mass storage device,
• (f) determine from the drive activity signal whether the mass storage device is active by sampling the drive activity signal to determine whether the drive activity signal is toggled between a first state indicating that the mass storage device is not connected and a second state indicating that the mass storage device is identified, the drive activity signal being active if the drive activity signal is toggled,
• (g) in response to determining that the drive activity signal indicates that the mass storage device is active, set a ready variable to indicate that the drive activity signal indicates that the mass storage device is active,
• (h) in response to determining that the drive activity signal does not indicate that the mass storage device is active, reset the ready variable to indicate that the drive activity signal does not indicate that the mass storage device is active,
• (i) determine whether the protocol variable is set to indicate that the decoded enclosure management data indicates that the mass storage device is active,
• (j) in response to determining that the protocol variable is set to indicate that the decoded enclosure management data indicates that the mass storage device is active, provide the activity indicator,
• (k) in response to determining that the protocol variable is not set to indicate that the decoded enclosure management data indicates that the mass storage device is active, determine whether the ready variable is set to indicate that the drive activity signal indicates that the mass storage device is active, and
• (l) in response to determining that the ready variable is set to indicate that the drive activity signal indicates that the mass storage device is active, provide the activity indicator.

A computer-implemented method for providing an activity indicator for a mass storage device, the computer-implemented method comprising computer-implemented operations for:

• receiving enclosure management data from a host bus adapter;
• decoding the enclosure management data to determine whether the enclosure management data indicates that the mass storage device is active;
• determining whether the decoded enclosure management data indicates that the mass storage device is active;
• in response to determining that the decoded enclosure management data indicates that the mass storage device is active, setting a protocol variable to indicate that the decoded enclosure management data indicates that the mass storage device is active;
• in response to determining that the decoded enclosure management data does not indicate that the mass storage device is active, resetting the protocol variable to indicate that the decoded enclosure management data does not indicate that the mass storage device is active;
• upon resetting the protocol variable, sampling a drive activity signal from the mass storage device at a frequency at least two times the frequency of the drive activity signal to determine whether the mass storage device is active, the mass storage device being active if the drive activity signal is toggled;
• in response to determining that the drive activity signal indicates that the mass storage device is active, setting a ready variable to indicate that the drive activity signal indicates that the mass storage device is active;
• in response to determining that the drive activity signal does not indicate that the mass storage device is active, resetting the ready variable to indicate that the drive activity signal does not indicate that the mass storage device is active;
• determining whether the protocol variable is set to indicate that the decoded enclosure management data indicates that the mass storage device is active;
• in response to determining that the protocol variable is set to indicate that the decoded enclosure management data indicates that the mass storage device is active, driving a light emitting diode corresponding to the mass storage device at a specified frequency;
• in response to determining that the protocol variable is not set to indicate that the decoded enclosure management data indicates that the mass storage device is active, determining whether the ready variable is set to indicate that the drive activity signal indicates that the mass storage device is active;
• and
• in response to determining that the ready variable is set to indicate that the drive activity signal indicates that the mass storage device is active, driving the light emitting diode corresponding to the mass storage device at the specified frequency.