An ATA-compatible drive interface with error correction and detection
capabilities is disclosed. Being fully ATA backward compatible, this
interface functions with the same physical cable and connectors as current
ATA systems, employs bus drivers that are the same as or backward
compatible with those provided by earlier versions of the ATA standard and
uses signals with cable signal transitions no faster than those presently
seen by current ATA devices. The error detection feature indicates when a
data block is erroneously transferred between the device and host; the
error correction feature identifies the words transmitted in error and
corrects those words on the receiving side of the interface. So that ATA
backward compatibility is maintained, the data integrity checking feature
does not require additional words in a data transfer, and the data
correction feature does not require new data transfer protocols or
additional data transfer overhead. Also disclosed are interface circuitry
and a new ATA-compatible transfer mode capable of transferring data at 40
MB/sec, the rate supported by local bus adapters for disk drives. Given
the physical limits of the ATA cables and connectors, the error correction
and detection features are especially useful for correcting data words
corrupted during high-speed transmission; however, error correction and
detection can also operate independently of the fast transfer mode.
Consistent with full backward compatibility, a hard drive configured with
the new, fast, error-correcting interface is transparently functional when
plugged into a current ATA adapter provided by a legacy computer system.