Cyclone II PS configuration problem

[Altera_Forum]

Hi all, 

 I am trying to configure 3 EP2C20 with 3 EPC2 device. The EPC2 device was configured with JTAG. So when the board power up the EP2C20 should be configured by the EPC2.  The connection is as per the altera website's Passive Serial interface...  nConfig: 10k ohm pull up nstatus: 10k ohm pull up conf_done: 10k ohm pull up MSEL1: GND MSEL0: 3.3V  The JTAG chain has 6 devices in total: EPROM1, FPGA1, EPROM2, FPGA2, EPROM3, FPGA3.   First I made a mistake of compiling the 3 devices with the option 'nCE0 as a programming pin' (i have it unconnected at the moment). The FPGA1 seem to be programmed (don't see nstatus and conf_done toggling) but not the other two.  Then after I recompile all 3 devices with 'nCE0 as a i/o pin' option, all three FPGA's conf_done and nstatus seem to be toggling, but the overall conf_done signal seem to be OK.   Please give me some advice? If there's anything not clear, please let me know. I will try to describe clearer if I can.  Thanks so much in advance!!  ETA: by the way, if I configure the 3 FPGAs with the *.sof file thru JTAG directly, there is no problem.

[Altera_Forum]

Hi 

I hope the cascadded conecction is perfect!!..  well I found this on Altera Cyclone handbook.. just check this up  The enhanced configuration devices’ and EPC2 devices’ OE and nCS pins have internal programmable pull-up resistors. If internal pull-up resistors are used, external pull-up resistors should not be used on these pins. The internal pull-up resistors are used by default in the Quartus II software. To turn off the internal pull-up resistors, check the Disable nCS and OE pull-ups on configuration device option when generating programming files.  Cheers

[Altera_Forum]

The cascadded connection should be fine, as we used this in another project before :) 

 Thanks for your info. I saw that too but somehow I read it is only for enhanced config devices (those EPC4, EPC8 etc).  I will give it a try and let u know :) Thanks a lot!

[Altera_Forum]

I just tried, it's so weird. 

 the first FPGA still has some problem configuring (conf_done or nStatus is still toggling) but the other 2 is fine. After I changed the first device with original file (did not disable OE, nCS etc), it seems to be OK now (conf_done or nstatus is HIGH).  ---- testing result:  it still seems to have some problem.  I really out of idea now.. let me get a pic of that cconfiguration circuit part later. Thanks.

[Altera_Forum]

Please see attached file. 

 all FPGAs/EPROM are connected this way, except for FPGA# 1 takes the CONF_DONE and nSTATUS of the other two device as inputs and has an single output of CONF_DONE to an LED.  What else is wrong? I am very frustrated.  Thanks in advance for any idea. :)

[Altera_Forum]

Hey  

Thanks for the upload.  Check this up....  The nINIT_CONF pin is available on enhanced configuration devices and has an internal pull-up resistor that is always active, meaning an external pull-up resistor should not be used on the nINIT_CONF to nCONFIG line. The nINIT_CONF pin does not need to be connected if its functionality is not used. If nINIT_CONF is not used, nCONFIG must be pulled to VCC either directly or through a resistor.  Hope this works!!...