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Altera_Forum
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14 years ago

What is wrong with EPCS4

In my custom board I connected EPCS4 device to Cyclone II on this order. Is this wrong because I was unable to detect EPCS4 device over JTAG. I only want to use JTAG, and in the cyclone II manual ...
Altera_Forum's avatar
Altera_Forum
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14 years ago

That is an AS+JTAG configuration scheme.

Can you detect the FPGA? If so, your JTAG chain should be OK.

It's normal that you can't detect the EPCS4 device via JTAG, as it doesn't even support JTAG.

EPCS can be accessed over JTAG using the Serial Flash Loader, but it doesn't show up in the JTAG chain.

Basically, the FPGA is first programmed with a firmware that include the SFL and then the EPCS is written through the FPGA, like this:

Quartus --> USB --> Byte Blaster --> JTAG --> FPGA --> AS --> EPCS4

To do this, you need to convert your .sof into a .JIC. Check AN370 for more details.