R8025AC is an early product, T is a later stage, are built-in crystal oscillator, it is said that the late T version is with warm, the two versions of the same pin, but the program is different can not be common1> test foot 8025T needs to be suspended, and 8025SA does not matter2> Different control bit3> The bit of a week is defined differently4> The frame format of the read and write data is different5> Data address High or low bytes 8025SA must be reversed, and 8025T must not be reversed