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Honored Contributor I
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MAX-II JTAG Chain issue

All, 

 

My setup: 

MAX-II EPM1270 

Quartus 9.0 

USB-Blaster 

 

I have designed my own Eval boards for the MAX-II EPM1270. I have no issues programming any of them by themselves. 

Now I have tried to connect each board together for the JTAG chain, and I get various errors. 

 

I have tried the textbook connection of 1K, 10K, 100K pullups on any, all, and some combinations to VCC on any and all 4 lines of TMS, TCK, TDI, TDO. I have also configured my setup as described in AN-428 MAX-II CPLD Design Guidelines page 7 which shows a 10K pullup to TMS and a 1K pulldown on TCK and TDI and TDO open... I have also tried different combinations of resistor combinations in this configuration, but I still have no luck. 

 

Sometimes I get an error: Unknowm integrity checking failure....... Then other times I can get it into a mode that shows 11, or 42, or 98, or..... devices in a chain, some with unknown and an IDs and others unknown. 

 

If I remove my jumpers from board to board and use each individual board by itself, everything is good and I can program each board individually all-day-long. 

 

My current design is going to consist of 4-MAX-II EPM1270s on one board and I was wanting to program them with only 1 header vs 4 headers. If I can't breadboard the "simple" JTAG chain, I will result back to 4 individual programming headers. 

 

Anybody have any ideas or suggestions?? 

 

Thanks, 

Keith
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