I have currently a problem with the MPC555 and this JTAG technologie.
In fact, I was in charge of developpement JTAG test for electronics cards. I developed a soft and an interface JTAG which used a PC parallel port. The communication JTAG between Boundary Scan Device is ok exept the communication with the MPC555.
According to the BSDL file of this component, when the communication is effective, the MPC555 must answer me "0101" but it's not the case.
At the first request it answers me, "0110"; at the second "1011" and at the third "1111" the further to the third it repeat in the same order the same bits...but not "0101" like is describe in the BSDL File...
So it's impossible for me to continu my project if I don't understand how this device works!
Please help me to understand this device.