Patent ID: 8234661

Claim:
An interface system, comprising: a secure digital input/output (SDIO) card; and a host including an SDIO driver module; a secure digital (SD) driver module; a multiplexer configured to allow communication between (i) the SDIO card and the SDIO driver module while the multiplexer operates in an SDIO mode, and (ii) an SD card and the SD driver module while the multiplexer operates in an SD mode; an input/output port independent of the multiplexer; and a bus control module configured to (i) set the multiplexer to the SDIO mode in response to the SDIO driver module acquiring a semaphore, (ii) set the multiplexer to the SD mode in response to the SD driver module acquiring the semaphore, and (iii) in response to receiving a notification signal from the SDIO card via the input/output port, request that the SD driver module release the semaphore, wherein the SD driver module attempts to acquire the semaphore in response to a request for access to the SD card, and wherein the SDIO card is configured to (i) selectively generate an interrupt, (ii) store the interrupt, (iii) in response to generation of the interrupt, transmit the notification signal to the bus control module via the input/output port independently of the multiplexer, and (iv) in response to the SDIO driver module acquiring the semaphore, deliver the stored interrupt to the SDIO driver module via the multiplexer.