MQX Software SolutionsのトピックMQX 4.2, Sd card Read Speed

MQX 4.2, Sd card Read Speed

aftab_s81 — Wed, 19 Apr 2017 10:39:40 GMT

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?

Re: MQX 4.2, Sd card Read Speed

danielchen — Wed, 19 Apr 2017 13:39:21 GMT

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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Re: MQX 4.2, Sd card Read Speed

aftab_s81 — Wed, 19 Apr 2017 14:54:59 GMT

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

MCF52254 MCU? I'm using MQX 4.2.