Patent ID: 7058741
Filing Date: 2006-06-06
Classification: G06F

Abstract:
1. A host apparatus comprising: an input/output part having a command signal line for transmitting a command signal from the host apparatus to an electronic device and a response signal from said electronic device to the host apparatus in response to said command signal, and a data line, at least a part of which is commonly used by plural electronic devices and connected to the plural electronic devices, for transmitting, at least, data in connection with the command signal from the host apparatus to said electronic device; and a control part having a saving register for bus release, wherein data is transmitted conforming to a protocol that the host apparatus serves as a master and said electronic devices serve as slaves, the host apparatus transmits a command signal to said electronic device and then said electronic device that received the command signal returns a response signal to the host apparatus and further, if necessary, data is transmitted from the host apparatus to the electronic device or from the electronic device to the host apparatus; and said control part in the state where one of said electronic devices is executing the processing that occupies said data line, when data transmission between the host apparatus and the other one of said electronic devices is intended to be executed, transmits a command signal for releasing said data line and suspending said processing to the electronic device that occupies said data line through said command signal line; stores an identifier of the electronic device that occupies said data line and the information on the current stage of said processing in said saving register for bus release; after completion of data transmission between the host apparatus and said other electronic device, reads out the identifier of the electronic device that had occupied said data line and the information on the current stage of said processing from said saving register for bus release; and transmits a command signal for returning to said suspended processing to the electronic device that had occupied said data line through said command signal line.