Hi Experts,
What is the maximum effective throughput that could be achieved in the SD/MNC host controller for the various IMX series of processors (IMX 3/5/6) ?
Is there any test suite for EVK or respective factory profiled value for the various platforms along with its associated scenarios ?
解決済! 解決策の投稿を見る。
The SD/MMC controller cores of the i.MX3x and i.MX5x series processors are pretty similar. They support the SD/SDIO v.2.0 specification and MMC v.4.2 specification. The Reference Manual documents for these processor series specify the following communication parameters of the SD/MMC controller cores.
— Card bus clock frequency up to 52 MHz
— Up to 416 Mbits/s of data transfer for MMC cards in 8-bit mode
— Up to 200 Mbits/s of data transfer for SD/SDIO cards in 4-bit mode
The SD/MMC controller cores of the i.MX6x series processors support the SD/SDIO v.3.0 specification and MMC v.4.41 specification. The Reference Manual documents for these processor series specify the following communication parameters of the SD/MMC controller cores.
Bus clock frequencies supported are:
- MMC full speed mode (up to 20 MHz)
- MMC high speed mode (up to 52 MHz)
- MMC DDR mode (52MHz both edges)
- SD/SDIO full speed mode (up to 25 MHz)
- SD/SDIO high speed mode (up to 50 MHz)
- SD/SDIO UHS-I mode(up to 208Mhz in SDR mode, up to 50Mhz in DDR mode)
The corresponding data rates are:
- Up to 832 Mbits/s of data transfer for SD/SDIO cards using 4 parallel data lines in SDR(Single Data Rate) mode
- Up to 400 Mbits/s of data transfer for SD/SDIO card using 4 parallel data lines in DDR(Dual Data Rate) mode
- Up to 832 Mbits/s of data transfer for SDXC cards using 4 parallel data lines in SDR(Single Data Rate) mode
- Up to 400 Mbits/s of data transfer for SDXC card using 4 parallel data lines in DDR(Dual Data Rate) mode
- Up to 416 Mbits/s of data transfer for MMC cards using 8 parallel data lines in SDR(Single Data Rate) mode
- Up to 832 Mbits/s of data transfer for MMC cards using 8 parallel data lines in DDR(Dual Data Rate) mode
There are no dedicated test cases for SD/MMC controller cores speed test, since the real data throughput depends on many factors, such as speed of device connected, software overhead etc.
Have a great day,
Artur
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Hi
I am going to use the Variscite DART6UL board for a project. It has the NXP i.MX 6 Ultralite ARM Cortex-A7 processor. I need to transfer data at 20MB/sec to a SD card.
Does anyone know if that kind of throughput rate is possible with the SD driver running and managing the file structure and writing operation to the SD FLASH memory?
I am concerned about the overhead the driver will impose on the overall data-rate.
Also, am I correct in assuming the data can be moved under DMA from a parallel input port to the SD bus?
Thanks in advance,
Dan
Hi Artur,
Thanks for the response.
The above mentioned items seems to be the ideal throughput value whereas I look for the actual throughput achieved beyond the signaling constraints in the SoC.
The SD/MMC controller cores of the i.MX3x and i.MX5x series processors are pretty similar. They support the SD/SDIO v.2.0 specification and MMC v.4.2 specification. The Reference Manual documents for these processor series specify the following communication parameters of the SD/MMC controller cores.
— Card bus clock frequency up to 52 MHz
— Up to 416 Mbits/s of data transfer for MMC cards in 8-bit mode
— Up to 200 Mbits/s of data transfer for SD/SDIO cards in 4-bit mode
The SD/MMC controller cores of the i.MX6x series processors support the SD/SDIO v.3.0 specification and MMC v.4.41 specification. The Reference Manual documents for these processor series specify the following communication parameters of the SD/MMC controller cores.
Bus clock frequencies supported are:
- MMC full speed mode (up to 20 MHz)
- MMC high speed mode (up to 52 MHz)
- MMC DDR mode (52MHz both edges)
- SD/SDIO full speed mode (up to 25 MHz)
- SD/SDIO high speed mode (up to 50 MHz)
- SD/SDIO UHS-I mode(up to 208Mhz in SDR mode, up to 50Mhz in DDR mode)
The corresponding data rates are:
- Up to 832 Mbits/s of data transfer for SD/SDIO cards using 4 parallel data lines in SDR(Single Data Rate) mode
- Up to 400 Mbits/s of data transfer for SD/SDIO card using 4 parallel data lines in DDR(Dual Data Rate) mode
- Up to 832 Mbits/s of data transfer for SDXC cards using 4 parallel data lines in SDR(Single Data Rate) mode
- Up to 400 Mbits/s of data transfer for SDXC card using 4 parallel data lines in DDR(Dual Data Rate) mode
- Up to 416 Mbits/s of data transfer for MMC cards using 8 parallel data lines in SDR(Single Data Rate) mode
- Up to 832 Mbits/s of data transfer for MMC cards using 8 parallel data lines in DDR(Dual Data Rate) mode
There are no dedicated test cases for SD/MMC controller cores speed test, since the real data throughput depends on many factors, such as speed of device connected, software overhead etc.
Have a great day,
Artur
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Note: If this post answers your question, please click the Correct Answer button. Thank you!
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