Connecting to image sensor

josephchen — Wed, 17 Sep 2014 00:28:27 GMT

Is it feasible to capture 720p video clips in the rate 30fps from image

sensor by K63 MCU and store into NAND Flash after JPEG

compression by DSP? Can the video be stored at least 5mins? Would

the performance acceptable? Or must I choose i.MX processor in this

case? What if I use external DDR2 to retrieve the clips? I want to know the limitation of this MCU.

Re: Connecting to image sensor

Hui_Ma — Wed, 17 Sep 2014 09:18:12 GMT

Hi Joseph,

K63 product doesn't have NAND flash controller, customer can select to use K60_100MHz product or K60_120MHz product for NAND flash access.

I get following data about Kinetis NAND Flash performance:

Write a page:

- NAND device write page typical time ~220us, max (Worst case) ~500us (tProg in Micron spec)

This time does not include data from NFC buffer to NAND device, this is the time that NAND device needs to program the array (2K+64).

- Move from NFC buffer to NAND: 2112 bytes @ NFC flash clock

- ECC is performed on the fly, so no ECC timing for encoding

- DMA data to NFCBuffer from CPU internal: 2048 + 64 @ CPU clock (11 CPU clock cycle every 32 bytes, 726 CPU clock cycles per page 2112 bytes)

Timing for a page write from CPU to NAND device till DONE bit is

:<DMA time @ CPU clock> + <NAND write command> + <NAND address command> + <DATA transfer @ flash clock> + <NAND device write page time>

So, min time will be: <726 * 10.42> + ~2us + ~2us + <2112 * 38.4> + ~220us = ~313us

And, worst time will be: <726 * 10.42> + ~2us + ~2us + <2112 * 38.4> + ~500us = ~593us

That means the typical NAND Flash performance is 6.24MB/s, the worst performance is 3.29MB/s.

I am not sure how many data need to transfer from JPEG compression(DSP) every second.

I think using K60_120MHz product or K70 with DDR2 memory is a correct choice. The DDR2 memory clock could up to 150MHz.

Wish it helps.
best regards
Ma Hui

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

topic Re: Connecting to image sensor in Kinetis Microcontrollers

Connecting to image sensor

Re: Connecting to image sensor