View Single Post
  #1 (permalink)  
Old 09-22-2006, 07:06 AM
Nevo
Guest
 
Posts: n/a
Default Configuration of Cyclone devices

Newbie alert here...

I'm trying to design a board that would allow me to configure a Cyclone
device either through the JTAG port or by downloading configuration data to
a serial configuration device. I'm looking at the manual and am trying to
reconcile differences between figures 13-9, "In-System Programming of Serial
Configuration Devices," and figure 13-19, "JTAG Configuration of a Single
Cyclone FPGA."

There are subtle differences in the two diagrams that I could probably guess
correctly on but would appreciate the feedback of the group.

1) 13-9 shows nCE to GND through a 10K resistor. 13-19 shows nCE to GND. I
assume I want to use the resistor?

2) 13-9 says Vcc pins should be connected to 3.3V supply (note 1). 13-19 has
no such indication. Should I tie all VCC on these two diagrams to 3.3V,
including pin 4 of the JTAG connector in 13-19? If I were looking only at
13-19, how would I know that VCC was 3.3V and not VCCINT?

3) Note 3 to 13-19 says VIO is connected to nCE when it is used for Active
Serial configuration with a ByteBlaster II cable. 13-19 shows nCE connected
to GND... <sheepishly> which means I just answered my first question; if I
don't use the resistor and program the device with a ByteBlaster II in
Active Serial mode I'll end up with a dead short between GND and VIO. Uh...
right?

I guess that more than anything I just want a sanity check from the group
before sending my artwork to the board shop.

Thanks!

-Nevo



Reply With Quote