STM32 Interface with FSMC and DMA

[ginnikhanna27]

Posted on March 21, 2012 at 12:56

Hi,

I have to read a 15 bit parallel data coming from a camera sensor and one bit as a request signal which tells whether the micrcontroller should initiate memory transfer or not.

Does FSMC has any trigger signal within itself so that I dont want to use any external interrupt or timer to trigger the transfer ?

Please help me out.

[registration]

Posted on November 22, 2013 at 20:32

Hello,

I'd like to use FTDI FT232H in FT245 synchronous mode, but in this case

the FT232 is the clock source, so I'm not able to use FSMC in synchronous mode

because the FSMC generates the clock. Therefore I would like to use the same

approach as written bellow, but my question would be could the Timer's capture

handle a 60MHz clock? 

Regards,

Daniel

[Tesla DeLorean]

Posted on November 22, 2013 at 21:10

I looked at the data sheets and got confused. You mean the FT2232H

http://www.ftdichip.com/Support/Documents/AppNotes/AN_130_FT2232H_Used_In_FT245%20Synchronous%20FIFO%20Mode.pdf

60 MHz is a tad on the high side for the external interface, certainly at or close to the limit for an STM32F2 device at 120 MHz. On a faster F4 device you'd need to contend with the resync on the input pins to get into the STM32's clock domain. The STM32F429 can get you up to 180 MHz, which again is a multiple of your clock.

Can you use a fractional version of the 60 MHz output to clock HSE_IN on the STM32? At least then you'd have a common view of time.

Are you planning on input, output or both?

[registration]

Posted on November 23, 2013 at 11:43

I have

http://www.ftdichip.com/Support/Documents/DataSheets/ICs/DS_FT232H.pdf

, but in that case It's the same.

I will use it with F4 series in bidirectional mode.

If I connect the CLK of the FT232H to the capture pin of the TIM3,

could It handle (TIM3 CC) a 60 MHz signal?

I will trigger the DMA transfer regarding.

Thanks,

Daniel

[Tesla DeLorean]

Posted on November 23, 2013 at 14:18

No, I don't think this is going to work.