topic Re: Can i use EIM for data transfer from FPGA? in i.MX Processors

Can i use EIM for data transfer from FPGA?

hanseunglee — Fri, 10 Jun 2016 02:32:57 GMT

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Ubuntu 12.04

Kernel 3.14

Yocto system

i.MX6DL sabresd board

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Hi everyone.

I want to data transfer from FPGA. (16bit data bus)

Can i use EMIF? If i want to use EMIF , what interface can i use?

MMDC? or WEIM?

I think to usually use EIM. right?

If the wrong decision, please tell us.

If i use EIM, can i use like below?

Can i have EIM example code or manual.. or other solution.. for data transfer use EIM from FPGA ?

Re: Can i use EIM for data transfer from FPGA?

igorpadykov — Fri, 10 Jun 2016 06:15:40 GMT

Hi Hanseung

you are right, one can use eim interface, for example codes one can

look at attached sdk test and pdf document Chapter 7 Configuring the EIM Driver

Best regards

igor

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Re: Can i use EIM for data transfer from FPGA?

hanseunglee — Fri, 10 Jun 2016 07:16:01 GMT

Thank you for your time!

Can i have a question?

Max operating frequency for EIM data transfer is 104Mhz.

if when i use multiplexed address/data mode, is EIM data trasfer rate 52 Mhz?

Do you know that data transfer rate for multiplexed mode?

Re: Can i use EIM for data transfer from FPGA?

igorpadykov — Fri, 10 Jun 2016 11:25:22 GMT

clock requirements are the same in multiplexed address/data mode

and timing diagrams can be found in datasheet and RM (EIM chapter).

Re: Can i use EIM for data transfer from FPGA?

andrewdyer — Tue, 14 Jun 2016 15:34:53 GMT

we used EIM in multiplexed mode with an FPGA to do 32-bit transfers and got avg. cycle times of 456ns for a read and 436ns for a write. The actual transfers were taking 156ns for read and 148ns for write and the i.MX6 was inserting about 300ns of delay between cycles (known issue discussed on these forums before). I suspect it would be possible to shave a few cycles off of the read and write times with more work, but this was sufficient for us.