ASYNCHRONOUS COMMUNICATION APPARATUS USING JTAG TEST DATA REGISTERS

摘要

PURPOSE: An IEEE 1149. 1 JTAG extending device and an IEEE 1149. 1 JTAG standard interface using method are provided to offer an asynchronous protocol for function circuit and interactive communication, and to detour a test circuit. CONSTITUTION: An IEEE 1149. 1 JTAG extending device comprises an integrated circuit(12) and a digital logic(18). The integrated circuit includes a function register and a JTAG standard test data register. The digital logic controls data direct transfer between the JTAG standard test data register and the function register.