Answers Database

Xchecker Cable: What is the CCLK circuitry in the Xchecker cable?


Record #1195

Problem Title:
Xchecker Cable: What is the CCLK circuitry in the Xchecker cable?


Problem Description:
When interfacing the xchecker cable to a custom PC board, it is sometimes import
ant to know the CCLK circuitry.


Solution 1:

The CCLK pin is driven by an IOB on the XC3042 inside XChecker.
It has the same sink/source characteristics as listed in the
3000 datasheets. The pin is terminated with 100 ohm, 100pF network as shown belo
w:

	--------
		|		100
		|-------+------\/\/\/-----O CCLK   to user's
	XC3042	|	|			     Board
		|      --- 100pF
	--------       ---
			|
			|
		       GND	




End of Record #1195