iMPACT initializes the JTAG chain and IDCODE looping operations successfully. After a programming attempt, iMPACT reports the following error:
"ERROR:iMPACT:2501 - Failed to initialize the <device_name> device."
The Status Register values are all 0. What is this problem occurring?
This error occurs if the PROG_B pin is pulled Low during programming. This causes the device to repeatedly clear configuration memory, which prevents programming. This behavior is not consistent for all Xilinx devices; it occurs in devices in which PROG_B does not affect the TAP controller. For devices in which PROG_B disables the TAP controller, iMPACT cannot access the JTAG chain. For more information on how PROG_B affects Xilinx FPGAs, see (Xilinx Answer 993).