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ronnywebers
Advisor
Advisor
1,120 Views
Registered: ‎10-10-2014

configuring MIO pins of SDIO interface 'slow' vs 'fast'

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I'm wondering if the SDIO interface pins in the Zynq IP config dialog should be set 'slow' or 'fast'? I'm using a 50MHz SD clock :

 

Picozed board def file  sets it to 'slow' :

 

MIO slow.jpg

 

but Zedboard for example sets these to 'fast' ..

 

Q : which setting is recommended for SD-card interfacing, and what exactly is the difference between 'fast' and 'slow', does this setting configure a different driver on the I/O pin?

 

 

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klumsde
Moderator
Moderator
1,186 Views
Registered: ‎04-18-2011

I would normally make the clock have the fast slew rate. the other outputs can be slow slew rate. 

in practice there is not very much in the difference.

a very simple IBIS simulation will show you

 

 

lvcmos18psmio_slew.JPG

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klumsde
Moderator
Moderator
1,187 Views
Registered: ‎04-18-2011

I would normally make the clock have the fast slew rate. the other outputs can be slow slew rate. 

in practice there is not very much in the difference.

a very simple IBIS simulation will show you

 

 

lvcmos18psmio_slew.JPG

-------------------------------------------------------------------------
Don’t forget to reply, kudo, and accept as solution.
-------------------------------------------------------------------------

View solution in original post