spartan 3xc3s4000 daisy chain help required

[colt45]

Hey,
i have daisy chained 2 FPGAs and 1 EEPROM but i cannot program them using JTAG mode. The error says" DONE pin did not go high". I have checked my circuit many times and i am sure that by now it's working fine but still the problem persists.
I am using the 2.5V settings i.e. no series resistors. The design is like this:

EEPROM -> XC3S4000 -> XC3S4000

i have connected EEPROM's TDO to first FPGAs TDI and so on.
Can anyone give me some pointers or any solution ?

also it would be nice to tell me the daisy chain configuration so that i can compare whether i am doing the right thing.

thanks

 

[colt45]

Added after 33 seconds:

The schematic is given above.. Kindly see it and help me out

 

[manosan]

Hi,

I was looking at your schematic.. I found two confusing signals...
where does JTAG-TDO and JTAG-TDI go...

The connections for daiy chaining is clearly given in Spartan3 datasheet or you can find configuraton details in Xilinx website..

 

[colt45]

JTAG TDO and JTAG TDI are going down the connectors. They have nothing to do here i guess..

 

[manosan]

I dont think so..

how will you program PROM then...

Wht i know is, the connection should be connector - prom - FPGA1 -FPGA2
TDI is the config bit input... Also the TDO of last FPGA should be connected back to connector.. There is some issue related to that as well...

 

[colt45]

The EEPROM is programmed through the JTAG interface.
And the chain is EEPROM - FPGA1 - FPGA2 ..