Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

Could some one explain some thing in this schematic please :)

Im very new to FPGA's and am using this attached schematic to crib from. every thing makes sense apart from the following FPGA pins pins 26,81 held high to 1.2v pins 27,80 held to ground ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

--- Quote Start ---

There is no reason for these signals to be pulled to ground or any other voltage. The pull-up to 1.2V is wrong, since 1.2V is not a valid logic level for a 3.3V I/O.

--- Quote End ---

The pinout file clarifies the point. As the text EP2C8 near the jumper already suggests, these pins have to be connected to GND and VCCINT when migrating to EP2C8. In so far, it's strictly required to connect them this way. The unusual point is to use jumpers in this place. Usually the migration pins would be connected directly to the power planes without jumpers if the design is prepared for the migration device.

Regards,

Frank