Anyone have any experience interfacing and controlling a Motorola MC145444
modem chip?  This chip has
a control port used to send commands (eg DTMF, FSK mode, Answer tone...)
via a 15 bit serial stream that is clocked into
an internal shift register then latched  The scope shows that my signaling
is valid but I can't get this chip to respond to any
command.  I would appreciate it if someone can help me make this thing
work.  I've been unable to find any applicable appnotes at Motorola's site.

Thanks,
Darrell