Kinetis Microcontrollers中的主题 Re: How to increase speed for SD card using SPI in FRDM-K20D50M board?

How to increase speed for SD card using SPI in FRDM-K20D50M board?

Amit_Kumar1 — Wed, 13 Nov 2013 03:57:11 GMT

Hello

I am trying to store some counting values to check the speed of data storage in SD card so for 1 minute the counter is showing values upto 327. Which I think is less for my use, I need to increase the speed how can it be done? I am attaching the snapshot of speed setting for the SD card library.

and that of clock setting is

After all effort the maximum speed I could get is around 25 Mhz in place of 24 MHz. Kindly look into the matter.

Thanks & Regards

Amit Kumar

Re: How to increase speed for SD card using SPI in FRDM-K20D50M board?

Jorge_Gonzalez — Wed, 13 Nov 2013 04:35:33 GMT

Hello Amit:

I got confused with your statement:

After all effort the maximum speed I could get is around 25 Mhz in place of 24 MHz.

Do you mean you need more than 25 MHz? or that the maximum you are getting is 24 MHz?

If you look at the K20 50 MHz datasheet, you can see the maximum frequency for SPI module is 25 MHz:

Hope this is somewhat useful.

Regards!

/Jorge Gonzalez

Re: How to increase speed for SD card using SPI in FRDM-K20D50M board?

Amit_Kumar1 — Wed, 13 Nov 2013 05:57:13 GMT

HI Jorge

Thanks for your reply. I wanted to Tell that earlier I was having 24Mhz frequency but after changing clock setting I was able to increase the frequency upto 25 MHz. Actually I am running simple counter i++ and printing the value of i in a SD card in .txt format so for each minute the counter is giving value around 327. which I think is very less. I wanted around 100 counts per second but I am getting only 5.45 count per second. So how to increase the speed ?

Regards

Amit Kumar