An integrated data storage control system provides, in a single integrated
circuit, RDC, servo logic, ATA interface, microprocessor, and other
formerly discrete components in one highly integrated system design. The
integrated circuit is rendered using a single integrated circuit
technology type (e.g., digital CMOS) for all components. Analog and
digital circuits are combined in such a way as to eliminate or reduce
noise or interference in digital circuits from analog circuit components.
Individual elements may have their outputs and inputs MUXed together such
that individual elements can be selectively switched (during testing
modes) such that the integrated circuit emulates or behaves in the same
or similar manner as one of the prior art components. The present
invention may be applied to magnetic hard disk drives (HDDs) or other
types of storage devices such as floppy disk controllers, optical disk
drives (e.g., CD-ROMs and the like), tape drives, and other data storage
devices.