Host device, storage device, and method for accessing storage device

Abstract

A host device is connected to a storage device via a bus and reads and writes data in the storage device. The host device includes a command transmitter that sequentially transmits a command in a command sequence, which includes a set of commands which do not change data stored in the storage device, and a response receptor that accepts a response from the storage device for each command transmission from the command transmitter and determines whether or not an error exists. An acceptable/unacceptable access determiner provided in the host device enables access to the storage device when a normal response is identified by the response receptor and otherwise determines that access to the storage device is unacceptable. The normal response is when the responses received from the storage device for the transmissions of all commands in the command sequence do not include an error.

1 . A host device which is connected to a storage device via a bus and reads and writes data in the storage device, the host device comprising:
 a command transmitter that sequentially transmits a command in a command sequence, which comprises a set of commands which do not change data stored in the storage device;   a response receptor that accepts a response from the storage device for each command transmission from said command transmitter and determines whether or not an error exists; and   an acceptable/unacceptable access determiner that enables access to the storage device when a normal response is identified by said response receptor and otherwise determines that access to the storage device is unacceptable, the normal response being when the responses received from the storage device for the transmissions of all commands in the command sequence do not include an error.   
     
     
         2 . The host device according to  claim 1 , wherein
 said command transmitter of said host device issues a plurality of command sequences.   
     
     
         3 . The host device according to  claim 2 , wherein
 said acceptable/unacceptable access determiner selects a command sequence that is different from the command sequence transmitted from said command transmitter, when it is determined that access is unacceptable.   
     
     
         4 . The host device according to  claim 3 , wherein
 said acceptable/unacceptable access determiner selects an acceptable command sequence that is transmitted from the storage device, when it is determined that access is unacceptable.   
     
     
         5 . A method for accessing a storage device by a host device, which is connected to the storage device via a bus and reads and writes data in the storage device, the method comprising:
 sequentially transmitting a command in a command sequence, which comprises a set of commands which do not change data stored in the storage device;   accepting a response from the storage device for each command transmission and determining whether or not an error exists; and   enabling access to the storage device when a normal response is determined and otherwise determining that access to the storage device is unacceptable, the normal response being when the responses received from the storage device for the transmissions of all commands in the command sequence do not include an error.   
     
     
         6 . The method for accessing a storage device according to  claim 5 , further comprising:
 selecting a command sequence to be transmitted, which is different from the command sequence previously transmitted, when it is determined that access is unacceptable.   
     
     
         7 . The method for accessing a storage device according to  claim 6 , further comprising:
 selecting an acceptable command sequence transmitted from the storage device, when it is determined that access is unacceptable.