Patent ID: 6253259
Filing Date: 2001-06-26
Classification: G06F,H04L

Abstract:
A data processing apparatus comprising:a serial signal I/O using serial signals for at least transmitting control command for controlling the operation of an external storage apparatus to said external storage apparatus, receiving a status signal indicating a state of the operation of said external storage apparatus from said external storage apparatus, transmitting data written to said external storage apparatus and receiving data read from said external storage apparatus;a control signal output for supplying, to said external storage apparatus, a control signal for controlling the timing of switching the data communicated by said serial signal I/O;a synchronizing signal output for supplying, to said external storage apparatus, a synchronizing signal of the data communicated by said serial signal I/O;wherein said control signal output makes the level of said control signal supplied to said external storage apparatus to be a predetermined level in accordance with the data communicated by said serial signal I/O,said data processing apparatus determines that the received status signal is a ready signal indicating that said external storage apparatus is in a state for waiting input of a signal in case that the level of said status signal is repeatedly changed at predetermined cycles, and in other cases determines that the received status signal is a busy signal indicating that said external storage apparatus is in a state in which said external storage apparatus does not receive an input of a signal.