I'm currently laying out a PCB containing a Spartan II-E (XC2S200E PQ208). I'm laying out the circuitry for an SPROM chip to store my bit file, but due to time constraints I would like to be able to program the chip using the JTAG interface (similiar to the one on the development board I am using, a Digilent development board from NuHorizons) in case, due to time constraints, I am unable to program the SPROM before a presentation.
I'm familiar with the way the JTAG cable works but am a little confused as to how the four pins (TMS TDI TDO TCK) interact with the FPGA. Based on my knowledge, I am assuming that the four pins are wired one to one with the corresponding FPGA input pins (and one output). The board I'm using has a parallel port to JTAG interface which makes tracing the port routes confusing. I really only have one or at most two shots at the PCB so I was just wondering if the JTAG pins can be wired directly to the FPGA, no buffer chip or anything in their way.
Thanks!
George