Hello All,
I am working on the device that was based on OMAP3503DCUS Processor running on Win CE 6.0 R2. The device was designed to support two micro SD slots. Internal and External Slots.
There was a requirement in order to make the device supporting the Wi-Fi SDHC Cards by replacing the external micro SD card. We made an add-on card for interfacing micro SD with SD form factor. Many test cases related to detection, Read/Write etc. have been formed to check all sort of Wi-Fi as well as normal SDHC cards. Now the issue is that the device fails in reading most of the cards thus would not be mounted. Please refer to the following test results.
|
Type of Card |
Result |
|
Transcend Class 4 SDHC Cards (4GB,8GB) |
Success |
|
Transcend Class 10 SDHC Cards (8GB) |
Success |
|
SanDisk 2GB SDHC Card |
Fail |
|
Toshiba Flash Air Class 6 Wi-Fi SDHC Card (8GB) |
Fail |
|
Toshiba Flash Air Class 10 Wi-Fi SDHC Card (8GB) |
Fail |
|
Transcend Class 10 Wi-Fi SDHC Card (16GB) |
Fail |
The same add-on card when connected to the Internal slot, all the cards were detected without any issue.
The main difference between Internal and External slots is that the Internal slot was connected to the in-built Transceiver of the processor whereas the external slot was connected to the external transceiver (TI’s SN74AVCA406DGGR). On debugging the SDHC driver code, it was found that there exists Data CRC error. The status of MMCHS_STAT register was not set properly that BRR (Buffer Read Ready) bit was not set. Even the block length argument was improper in the command send to Host Controller where this was not the case with detected cards. Even we had tried with different clock frequencies but in vain.
Please respond if someone faced the same issue and had a solution.
Thanks in Advance
