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Altera_Forum
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14 years ago

config fpgas with other fpga in AS mode

When I config FPGAs with other FPGA in AS mode,I met troubles below. When I select 3.3v LVTTL as IO STANDARD,the phenomenon is as below. FPGA-1 : the DCLK pin's voltage is about 3.3v FPGA-2 : ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

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But if you don't connect DATA0 (EPCS data output) at the master FPGA, you aren't able to verify the EPCS programming or check for busy state during programming.

Referring to the origibal problem, I presume that you are pulling nCE high during EPCS access?

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I had pull nCE high and nCONFIG low during EPCS access.

the VCCIO is 3.3v,and I set IO Standard to be 2.5v.does it matter?

the Max current strength is also diffrent between 2.5v IO Standard and 3.3v IO Standard.

(3.3v -> Max current strength = 8mA;2.5v -> Max current strength = 16mA)