Compliance Values for JTAG Devices

Related to Constant Pins and Bus Disable Values are Compliance patterns in BSDL files, which cause certain pins on a JTAG device to take a Compliance Value. This value specifies what must be set to a pin for the JTAG device to be in its JTAG mode. Typically if the values on these pins are changed, the device will exit JTAG mode and begin normal operation, which is generally undesirable during JTAG testing.

XJTAG treats Compliance values like constant pins, and like constant pins they can be overridden during XJEase testing by explicitly setting a bus to a different value.

Constant pins defined by the user have higher priority than Compliance values. You should therefore take care setting constant pins because it is possible to accidentally set a constant value which prevents a JTAG device from operating correctly.