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Dear Sirs! I work at my first "standalone_C164_tool"and got in trouble,could someone please check if I'm right with this Hardware (Pin)-configuration: EA =high -for single chip mode (does Port0-levels takes effect on something?-At my board it's still doing for example on the clockconfig.!-I thought it should not. NMI and RSTIN =high (I think otherwise there will be a permanent reset?) That's all I have done -I think C164 works now out of the OTP with the clock frequency of the crystal . The next big problem: The crystal starts oscilating some seconds (20MHz)and than stops-or looks like random noise. Because that I changed the capacitors from 12 to 20 pF (it changed nothing) I tried some resistors between XTAL2 and crystal (ca.120 Ohm) and some Resistors between the two pins of the crystal (100k to 600k).The current becomes extreme different values(between 70mA until 210mA with oscilating crystal-when it stoped oscilating the current sinks to 60-70 mA) What could be wrong here?-the chip is good at the board,so it's not damaged.I tried different crystal with 5,10 MHz-that changed nothing.Perhaps the Port0 configuration isn't 'disabled'? Is someone familiar with that? Please help me! Thanks! hannes
Hello Hannes, for crystal oscillator, start from Infineon Appnotes, look here http://www.infineon.com/cmc_upload/documents/009/746/ap242005.pdf Anyway, crystal capacitors depend on crystal, not on C164 oscillator; maybe you can try greater value capacitors, up to 47pF, or try to find your crystal specifications and look what values are suggested. Again, as we said in the past, external P0 configuration was still used on certain (older) steps of the C164, so check your step. EA = 1, NMI = 1 and RSTIN acting as a normal reset (initially low and then high to start the chip) are OK. Ciao Bruno