Some problems about Configration and board debug

[Altera_Forum]

Hello , everyone , I have designed a board , which contains four Stratix 2 devices (EP2S180F1020C5N) , I have added some wires between them and tied directly to the IOs of each device . Also I have added several switches to change the configration mode : AS or JTAG , respective or chain . First , I just weld only one device on the board and verification some fuctions of my design such as configration ,the power system of the device and so on , the resuit shows that it Ok . Then I have weld the rest 3 devices on the board , however , problems occur as follows : If I download the .sof file to one of the device (the other JTAG interface are shut down by swiches) via JTAG interface , the Quartus shows dowload successful , but after download 100% , the device has no responce ; If I download the .jic file , the Quartus shows operation failed ; If I download the .pof file via AS interface ,the Quartus shows download successful and the device has no responce too . The wires which are JTAG related of each devices can be separated by the switches , the wires which are AS related of each device except DCLK and DATA can also be separated by the switches . Each device has some IOs (I ensure they are User IO ) tied directly to other's . I am mazing why I succeed before and failed when all of the device are welded on the board even if I power off the rest 3 device .

[Altera_Forum]

How about the config_done signals ? How did you wire these 4 signals, together or indepent?!

[Altera_Forum]

And pls provide the config_done's status!

[Altera_Forum]

Hello jerry , thanks for your kind-hearted reply ,the conf_down ,nstatus , nconfig pins of the four device are tied together ,and by a 10k resistor pull up to 3.3v(as the description of the attchment) ,i know this types of design my cause jtag chain configration failed ,but according to the handbook ,this won't affect the muti-device as configration ? i have check the status of conf_down ,nstatus after as configration , both of them operate at a status of low .

[Altera_Forum]

For your Config_done signals are wired together, all the devices can't be released after that all the devices are configured correctly. The config_done signal is controlled by one device when there is only one FPGA is welded. But the config_done signal would be contolled by all FPGAs when all 4 deivces are welded.

[Altera_Forum]

I have a recommendation, you can config all 4 devices each time when want to debug.