When using the USB or parallel ispDOWNLOAD cables, connect the "flywire" signals:
VCC, TDO, TDI, TMS, GND, and TCK. ispEN (Enable Pin) and ispTRST (Reset Pin) are required for some older devices.
Reference the datasheet of a specific device to determine if these two pins are required.
Optional signals, which are typically used in FPGA devices:
PROG - enables device to be programmed
INIT - device ready to be programmed
DONE - indicates status of configuration