MQX 4.2, Sd card Read Speed

[aftab_s81]

Hello,

We are using MQX 4.2, on a MCF52254 based custom made board.

We are trying to read data from sd card. This is audio data so we require real time performance. The data is read through following command:

bytesRead = read(mfs_fp, buffer, MP3_READ_SIZE);

We have observed that it takes a minimum of 11ms to read a data chunk of 2048 bytes, i.e, ~186kB/s of data read rate. We are measuring the time thru _time_get commands. We think that, this is way too slow. Is there a way to improve it?

[danielchen]

Hi Aftad:

We have data for eSDHC speed on K70, unfortunately we don't have data on MCF52254,

Please refer to below picture for Maximum MFS Speeds over eSDHC on K70.

The performance can be increase by using multiple w/r blocks. But just to let you know that the performance depends on SD you are using, if you try with other SD, the performance maybe vary.

Have a great day,
Daniel

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[aftab_s81]

Do you think 186kB/s data read from any sd card is realistic with

MCF52254 MCU? I'm using MQX 4.2.