Patent ID: 7124219

Claim:
An external connection device connectable to a host device, said external connection device comprising: a parameter register for storing a parameter; a command register for storing an operation control command; and a controller for referring to the operation control command stored in the command register and for performing operation control as specified by the operation control command; said parameter register and said command register being selectively accessed by the host device based on a memory access transfer protocol command (TPC) issued by the host device and a security management transfer protocol command (TPC) issued by the host device; the memory access TPC including a register write command for transferring an arbitrary operation control command from the host device to said external connection device and for storing the transferred operation control command in said command register; the security management TPC including a register write command for transferring an arbitrary operation control command and an arbitrary parameter from the host device to said external connection device, for storing the transferred operation control command in said command register, and for storing the transferred parameter in said parameter register.