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Altera_Forum
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18 years ago

Connecting 3.3V IO to 1.2V for pin compatibility

Hi, I am designing a board containing a CycloneII FPGA. I am not sure which part numer i should to use, 35 or 50. These two parts are pin compatible except that some pins are used as VCCINT(...
Altera_Forum's avatar
Altera_Forum
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18 years ago

ON the Same Assignments Device page, there is also a box called "Device and Pin Options".

On the Unused Pin Tab - You may need to change the selection from the default of "As output driving Ground" to something like "As input tri-state with weak pull up" so that in the package where the pins are connected to Vccint (1.2v) you do not have an un-used I/O not driving this to ground.