External connection device, host device and data communication system
AssigneeSony Corporation
InventorHideaki Bando
Life of this patent
Estimating the term…
Abstract
This invention is an information processing device such as a computer, as a host device, and a memory card as an external connection device to be connected to the host device. A memory card (1) and a host device (2) are connected with each other in accordance with a six-wire-system half-duplex protocol using four-bit parallel signals, a bus state signal, and a clock signal. When the state of the bus state signal is a state of accepting interruption, the memory card (1) sends an interrupt signal (INT) to four-bit parallel buses. Different elements of interruption are allocated to the respective bits of the four-bit parallel signals. That is, the bit at which the INT signal is sent varies depending on the content of interruption.
Claims3
A data communication system comprising a host device and an external connection device to be connected to the host device,
- the host device comprising data communication means for performing bidirectional communication of transmission data to and from the external connection device via a data bus, bus state signal sending means for sending a bus state signal indicating the state of the data bus to the external connection device, and a controller for issuing a control command for controlling an operation of the external connection device, the control command being included in the transmission data,
- the external connection device comprising data communication means for performing bidirectional communication of transmission data to and from the host device via a data bus, bus state signal receiving means for receiving a bus state signal indicating the state of the data bus from the host device, and a controller for controlling the operation of this device in accordance with an operation control command included in the transmission data,
- wherein when the state of the bus state signal is a state of accepting interruption from this device to the host device, the data communication means of the host device and the external connection device send, from the external connection device to the host device via the data bus, information indicating the content of an element of interruption generated on the basis of the operation control command provided to the external connection device from the host device.
Dependencies are inferred from the claim text.