GENERAL DESCRIPTION
The PCD5091 is designed for GAP-compliant handsets with speaker-phone option. It has an embedded 80C51 microcontroller with twice the performance of the classic architecture, 64 kbytes of PROM program memory and 3 kbytes of data memory on-chip. In addition there is 1 kbyte of on-chip data memory that is shared with on-chip Burst Mode Logic (BML) and DSP, the System Data RAM (SDR).

FEATURES
• 80C51 ports P0, P1, P2 and P3 available for interfacing to display, keyboard, I2C-bus, interrupt sources and/or external memory. Integrated 64 kbyte ROM, 3 kbytes of data memory and 1 kbyte SDR-RAM. External program memory is addressable up to 128 kbytes
• +2.7 to +5 V port (P0 to P3) interface
• TDMA frame (de)multiplexing. Transmission or reception can be programmed for any slot
• Ciphering, scrambling, CRC checking/generation and protected B-fields
• Speech and data buffering space for six handsets
• Local call and B-field loop-back
• Two interrupt lines for BML and DSP to interrupt 80C51
• On-chip, three-channel time-multiplexed 8-bit Analog-to-Digital Converter (ADC) for RSSI measurement, one for battery voltage measurement and one channel available for other purposes
• On-chip 8-bit Digital-to-Analog Converter (DAC) for electronic potentiometer function
• Phase error measurement and phase error correction by hardware
• DACs and ADCs for dynamic earpiece and dynamic or electret microphone
• On-chip reference voltage
• On-chip supply for electret microphone
• Very low ohmic buzzer output
• Serial interface to external ADPCM CODEC (PCD5032) or 8 kHz u-law samples
• Speech switch for Digital Telephone Answering Machine (DTAM) connected to SPI interface
• IOM-2 interface (Siemens registered trademark)
• Serial interface to synthesizer for frequency programming
• Programmable polarity and timing of radio-control signals
• GMSK pulse shaper
• Easy interfacing with radio circuits, operating at other supply voltage (RF supply pin with level shifter for RF signals)
• On-chip comparator for use as data-slicer
• Low power oscillator with integrated frequency adjustment
• QFP100 and LQFP100 packages
• Power-on-reset
• Programmable power-down modes
• Low supply voltage (2.7 to 3.6 V)
• CMOS technology.