AN 509: Multiplexing SDIO Devices Using Altera MAX Series

ID 683683
Date 9/22/2014

1.2.3. Setting up SD Host/Card Reader to Work with The MDN-B2 Demo Setup

To set up the SD host/card reader to work with the MDN-B2 demo setup, perform the following steps:

  1. Use a general purpose USB SD card reader modified to access the card detect line from its SD socket.
  2. Ensure that the USB cable to the SD card reader is disconnected and the power switch on the MDN-B2 is turned off.
  3. Fix the SD card-shaped PCB adapter in the SD card reader’s SD socket, and then insert two SD memory card devices in the two SD sockets on the MDN-B2.
  4. Connect the card detect line tapped from the SD card reader to the MDN-B2 board through pin 5 on JP8.
  5. Turn on the MDN-B2 and then connect the USB cable to the SD card reader.
    “My Computer” on the PC to which the card reader is connected shows one of the SD memory cards.
  6. Using the parallel port utility, perform a write operation into the I2C slave.
    Observe the corresponding changes in the “My Computer” listing of the appropriate SD memory card that was multiplexed.
  7. To do a write I2C operation, press Start followed by Write Byte. Enter hex byte 00 in the field adjacent to Write Data and click Write Data.
  8. This will select one of the SD devices. Similarly, writing FF will select the other SD device. LED D12 on the MDN-B2 will change its state accordingly.