Method for operating a TAP controller and corresponding TAP controller

TAP controller having:

• a first input terminal (Etms) for inputting a logic test mode selection signal (tms) and a second input terminal (Etrst) for inputting a logic reset signal (trst);
• the TAP controller being configured in such a way that it is in a test mode if the test mode selection signal (tms) has a first logic state (“0”), and it is in no test mode if the test mode selection signal (tms) has a second logic state (“1”), that it is reset asynchronously from the test mode into the non-test mode by single application of the logic reset signal (trst) with the first logic state (“0”);
• a first signal pad (Prst) for providing an external logic reset signal (reset_n);
• a second signal pad (Ptms) for providing the logic test mode selection signal (tms);
• an inverting device (INV), which is connected to the second signal pad (Ptms) for inverting the logic test mode selection signal (tms);
• and
• a logic ORing device (OR), which is connected to the first signal pad (Prst) at the output of the inverting device (INV), for forming a logic ORing of the external logic reset signal (reset_n) and the inverted logic test mode selection signal (tms*) and for generating the logic reset signal (trst);
• the logic reset signal (trst) generated by the logic ORing device (OR) being applied to the second input terminal (Etrst).