1226 - Radiant Programmer: What programmer detected Lattice device as "JTAG-NOP"?
JTAP-NOP indicates that a device was detected, but its JTAG IDCODE is not available in software device database. There are a few reasons this may occur:
1. The device is a newer Lattice device and is not yet supported by the software tool version used. Installing the latest version of Radiant will update to the most recent device database.
2. The device is from another vendor. Non-Lattice devices can exist in the chain and be bypassed. The instruction register length of these devices must be specified. The user can either enter a known value for the device manually or import the BSDL file available from the manufacturer.
3. The JTAG IDCODE of devices in the chain were misread due to signal quality problems. False edges on TCK or voltage incompatibilities are examples of issues that may cause this. The programming cable should also be connected to an appropriate power supply and stable ground reference to ensure proper generation and detection of the JTAG signals.