Altera CLKLK_FB use when OPERATION_MODE=NORMAL

I put this up on altera's site. They answered:

OK, when the ALTCLKLOCK is in Normal mode, CLKLK_FB inputs are not used by the PLL (i.e. the PLL ignores the external FB pin).

However, you cannot use the CLKFBIN pin (R6 for your device EP20K200EFI484-2X) as a general purpose I/O, as it is a dedicated input pin for use with the PLL only. (in the pinout file generated by Quartus this pins usage will be designated with a GND+ which means this pin should be connected to GND if unused.

Note however that pin P6 (CLKLK_FB2n) can be used as a general purpose I/o, as this is not a dedicated input pin.

Take care!!!

- Paulo Valentim

I put this up on altera's site. They answered:

OK, when the ALTCLKLOCK is in Normal mode, CLKLK_FB inputs are not used by the PLL (i.e. the PLL ignores the external FB pin).

However, you cannot use the CLKFBIN pin (R6 for your device EP20K200EFI484-2X) as a general purpose I/O, as it is a dedicated input pin for use with the PLL only. (in the pinout file generated by Quartus this pins usage will be designated with a GND+ which means this pin should be connected to GND if unused.

Note however that pin P6 (CLKLK_FB2n) can be used as a general purpose I/o, as this is not a dedicated input pin.

Take care!!!

- Paulo Valentim

I put this up on altera's site. They answered:

OK, when the ALTCLKLOCK is in Normal mode, CLKLK_FB inputs are not used by the PLL (i.e. the PLL ignores the external FB pin).

However, you cannot use the CLKFBIN pin (R6 for your device EP20K200EFI484-2X) as a general purpose I/O, as it is a dedicated input pin for use with the PLL only. (in the pinout file generated by Quartus this pins usage will be designated with a GND+ which means this pin should be connected to GND if unused.

Note however that pin P6 (CLKLK_FB2n) can be used as a general purpose I/o, as this is not a dedicated input pin.

Take care!!!

- Paulo Valentim