UMF1000T

The UMF1000T has the following features including Single chip solution to all the data handling and supervisory;functions;Configuration to both AMPS and TACS;All analog interface and filtering functions fully implemented on chip;Error handling in hardware reduces software requirements;Robust SAT decoding and transponding circuitry;Low current consumption;Small physical size;Minimum external peripheral components required.

The UMF1000T is a low power CMOS LSI device incorporating the data tranceiving, data processing,and SAT functions (including on-chip filtering) for an AMPS or TACS hand-held portable cellular radio telephone.The UMF1000T (DPROC) is a single-chip CMOS device which handles the data and supervisory functions of an AMPS or TACS subscriber set.In an AMPS or TACS cellular telephone system, mobile stations communicate with a base over full duplex RF channels. A call is initially set up using one out of a number of dedicated control channels. This establishes a duplex voice connection using a pair of voice channels. Any further transmission of control data occurs on these voice channels by briefly blanking the audio and simultaneously transmitting the data. The data burst is brief and barely noticeable by the user. A data rate of 10 kbits/s is used in the AMPS system and 8 kbits/s in TACS. The signalling formats for both Forward Channels (base to mobile) and Reverse Channels (mobile to base) are shown in Fig.3.

The number of data bytes transferred between the start and stop conditions from transmitter to receiver is not limited. Each byte of eight bits is followed by one acknowledge bit. The acknowledge bit is a HIGH level put on the bus by the transmitter whereas the master generates an extra acknowledge related clock pulse. A slave receiver which is addressed must generate an acknowledge after the reception of each byte. Also a master must generate an acknowledge after the reception of each byte that has been clocked out of the slave transmitter.