Hi everyone,
did someone get the Keil USB-MSD example working with the MMC/SD interface? I got the reading of an MMC/SD working but I know that this is the easy part. I appreciate any feedback or advice to get this task solved quickly.
In case someone from Keil reads this posting: Does Keil plan to provide a extended example for the USB-MSD class probably involving the MMC/SD interface?
Thank you, Frank
Short answer: Buy this book and learn about MSC "USB Mass Storage: Designing and Programming Devices and Embedded Hosts" by J.Axelson http://www.lvr.com/usbms.htm
If you are lucky, you can read the interested pages over Gooooogle book :-) http://books.google.com/ Search the keyword "USB Mass Storage Axelson"
(A little) Long answer: Outline of MSC-BOT (Mass Storage Class - Bulk Only-Transfer)
MSC carries SCSI command from host to device over USB. On the device, a command parser executes these SCSI commands. The minimal SCSI commands required are just these six commands. - Inquiry, Request Sense, Test Unit Ready, Read(10), Read Capacity, Write(10)
www.usb.org/.../MSC-compliance-0_9a.pdf Table 1 Required and Optional Commands (MSC-compliance-0_9a.pdf p13)
Then, find the command dispatcher on the MSC example, and implement these SCSI commands for the MMC/SD. You'll find many examples to know how to implement these commands for MMC/SD. Because it is a common procedure, any example for any USB MCU will do.
When the firmware gets this class-specific request, Bulk-Only Mass Storage Reset, stop the current command execution and initialize the MMC/SD-handling task.
Tsuneo
Hi Tsuneo,
thank you for your reply. The book "USB Mass Storage Axelson" seems to be a good source for all the required details.
I will return to this forum in case I experience problems. Hopefully you will be around.
Frank