I have the problem that I can't communicate with my Xilinx XCF04S PROM through JTAG. The circuit setup is a "3.3V Master-Serial Configuration with 3.3V and JTAG with Platform Flash Prom" as here:To reduce the sources of error, I disconnected the JTAG input signals TMS, TCK, TDO to the FPGA, and connected the TDO directly from the PROM to the connector, therefore bypassing the FPGA. According to the PROM datasheet, the only pins that matters additionaly to the JTAG signals is the #CE pin (this pin is always low) and power pins. I checked with an oscillator the JTAG signals:
All JTAG signals toggel (i measured on the IC and connector to exclude any soldering problems). I noticed that TDI and TCK look very similar, however there is not short-cut between them
When I do an ID Check, i get this:
INFO:iMPACT:1578 - '1': Device IDCODE :00001111111111111111111111111111 INFO:iMPACT:1579 - '1': Expected IDCODE: 00000101000001000110000010010011
I would like to have your opinions what you think the error is?
Thank you, Jidan