Abstract: A transmitter (604) of a TDMA cellular telephone (600) includes power control circuitry (100) comprised of variable gain stage (104), mixer (106), bandpass filter (109), RF amplifier (110), and directional coupler (112) in a forward path, and two detectors (116 and 117), four A/D converters (118, 119, 121 and 123), digital controller (120), and D/A converter (126) in a feedback path. In operation, the variable gain stage (104) is responsive to a gain control signal AOCCNT (128) for adjusting a modulated IF signal, which is then mixed in mixer (106) with an RF reference signal to produce the transmit RF signal. The temperature and supply voltage are sampled by controller (120) at the beginning of each time slot. Adjustments in the gain control signal (128) dictated by the sampled temperature and supply voltage are made by controller (120) in each time slot prior to keying the RF amplifier (110).

Abstract: A multiplexed synchronous/asynchronous data bus is disclosed in which three bus lines are used to convey bidirectional synchronous data between at least two data devices at a relatively low data rate. Valid half duplex asynchronous data is applied at a higher data transfer rate to one of the three bus lines when only one of the bus lines is held in a logic high state.

Abstract: A multiplexed synchronous/asynchronous data bus is disclosed in which three bus lines are used to convey bidirectional synchronous data between at least two data devices at a relatively low data rate. Half duplex asynchronous data is applied at a higher data transfer rate to one of the three bus lines when another of the bus lines is held in a logic high state.

Abstract: An analog frequency inversion scrambler employing an exchange of random number seeds between an originating scrambler and an answering scrambler to create two pseudo-random frequency hopping rolling codes has been disclosed. The rolling code used in one direction of a duplex channel is different than the rolling code in the opposite direction and each code is synchronized by periodic synchronization signals.