Patent ID: 8468370

Claim:
A data storage device comprising: a power circuit configured and arranged to provide main power; a first solid-state memory circuit configured and arranged to maintain data in the absence of electrical power; a second memory circuit subject to data loss in the absence of electrical power; a storage circuit configured and arranged to store energy in a storage element and to provide the stored energy to the second memory circuit in response to a loss of main power; a test circuit electrically connected to the storage circuit to: modify how much energy is stored on the storage element, by enabling a load to cause a discharge of at least some of the stored energy in response to a test enable signal, monitor power-providing capabilities of the storage element during the modification of energy stored, and provide, in response to discharging, output data indicative of power providing capabilities of the storage element, wherein the output data is in the form of multiple interrupts in response to determining that the power-providing capabilities are below threshold levels; and a memory controller configured and arranged to: receive data access requests over a hard-drive interface, control, for the received access requests, data transfers to the data storage device by temporarily storing, in the second memory circuit, data destined for the first solid-state memory circuit, and in response to the output data, set an amount of memory available for temporary storage in the second memory circuit.