Druzyek
Newbie
I'm trying to program an ATF1508 using JTAG signals generated by a microcontroller. I can read the IDCODE myself. When I try to program an SVF file it also includes the instruction to read the IDCODE, which succeeds. It has a few hundred other instructions then reads in data 41 bytes at a time, expecting the same data to be echoed back. The very first one echoes back the IDCODE first before echoing the data back. Do JTAG devices ever do this to signal an error?
It could be a problem with my circuit, although I doubt this since the IDCODE instruction succeeds. I'm using a 3.3v microcontroller and level shifting with 2N2222 transistors pulled up to 5v with 10k resistors. I don't think it's a timing issue since I get the same results with a 1ms delay before, during, and after clock transitions.
It could be a problem with my circuit, although I doubt this since the IDCODE instruction succeeds. I'm using a 3.3v microcontroller and level shifting with 2N2222 transistors pulled up to 5v with 10k resistors. I don't think it's a timing issue since I get the same results with a 1ms delay before, during, and after clock transitions.
