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14 years agoEP4CE6F17I8LN no JTAG, nSTATUS stuck low
Hello All,
I have an interesting Cyclone IV problem. I'm using an I8LN by accident. I bought the wrong device; I'm using 1.2V for Vcore - when the 'L' part specifies 1.0V. My understanding is that it should still work... right? I just won't realise low power. Certainly JTAG should be happy...? My symptoms: - no jtag access according to programmer/jtag debugger - activity on TCK, TMS, TDO, TDI, none are stuck, my blaster works fine - TMS, TDI - 10K pull up to 2.5V - TCK - 1K pull down to GND - nCE - driven hard GND - nSTATUS is 0V - it has a pull up 10k to 2.5V - with power removed, this pin has about 10Kohm to GND - so no placement problem - nCONFIG is 2.5V and has a 10k pull up to 2.5V - CONFIG_DONE is 2.5V and has a 10k pull up to 2.5V - MSEL2,1,0 = 010 = AS standard POR delay. - All power rails from linear supplies, 3.3V, 2.5V, 1.2V nice and clean. As far as I can tell I'm doing every (except the core voltage by the book.) Is this enough to sink my boat? Any tips would be greatly appreciated.