Cyclone III Starter Board clock input

[Altera_Forum]

This starter board is having a Cyclone III EP3C25F324 device with a 50MHz oscillator supplying the clock signal. For my project we would like to use an oscillator with a higher frequency stability. After searching on web, we found only 100MHz with the desired stability is available. My question is, can I use the 100MHz oscillator to replace the existing one, and inside my project, I simply generate 50MHz clock based on the 100MHz source? After I change the oscillator, will I still be able to program the FPGA through Quartus (or will that affect the JTAG programming)? Thanks.

[Altera_Forum]

Changing to a 100MHZ oscillator should be fine provided it matches the I/O interface specification (e.g. 2.5V, 3.3V, LVTTL, LVCMOS, or whatever). It will not affect JTAG programming.

[Altera_Forum]

Hi gfeng_tf, 

 Like what gj_leeson has mentioned, generally changing oscillator would not cause issue to JTAG programming. However, it is recommended for you to review the board schematic to understand what are the components driven by the original 50MHz oscillator and how the change in frequency affect the other components on board.