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How to determine frequency of 8-pin DIP oscillator in Spartan-3E ?

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Spartan-3e has 3 clk sources, on-board 50MHz crystal, 8-pin DIP oscillator & SMA input.
As I m using the 10/100 Ethernet port, it requires clk >65MHz, so I cannot simply use the on-board 50MHz clk. I would like to know:
1. 8-pin DIP oscillator - I suppose this is normal 8-pin oscillator/timer right? How to determine the frequency of the clock?
2. Besides 8-pin DIP, d documentation mentioned something about DCM, what is it anyway?
 

spartan 3e 50 mhz

Spartan-3E is an FPGA type. Which board do you have?

I'm guessing you have the Xilinx/Digilent Spartan-3E Starter Kit. Its Ethernet PHY runs from a 25 MHz crystal. It does not require 65 MHz.

I'm also guessing you are reading a paragraph in the board's user manual regarding the Microblaze MAC core. Apparently, the core's OPB bus needs to run at least 65 MHz. There are other ways of talking to the Ethernet PHY chip besides using that core.

If you need a higher frequency than 50 MHz, you could configure a DCM as a frequency multiplier. To learn more about DCMs, read chapter 3 "Using Digital Clock Managers" in your "Spartan-3 Generation FPGA User Guide".
 

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