FX919A

CML Semiconductor Products www.DataSheet4U.com 4-Level FSK Modem Data Pump FX919A D/919A/4 June 1996 Advance Information 1.0 Features 4-Level FSK Modulation Half Duplex, 4800 to 19.2k bits/sec Full Packet Data Framing Flexible Operating Modes Host Bus Interface Low Power 3.3V to 5V Operation 24-Pin Small Form Package Option 1.1 Brief Description The FX919A is a CMOS integrated circuit that contains all of the baseband signal processing and Medium Access Control (MAC) protocol functions required for a high performance 4-level FSK Wireless Packet Data Modem. It interfaces with the modem host processor and the radio modulation/demodulation circuits to deliver reliable two-way transfer of the application data over the wireless link. The FX919A assembles application data received from the processor, adds forward error correction (FEC) and error detection (CRC) information and interleaves the result for burst-error protection. After adding symbol and frame sync codewords, it converts the packet into filtered 4-level analogue signals for modulating the radio transmitter. In receive mode, the FX919A performs the reverse function using the analogue signals from the receiver discriminator. After error correction and removal of the packet overhead, the recovered application data is supplied to the processor. Any residual uncorrected errors in the data will be flagged. A readout of the SNR value during receipt of a packet is also provided. The FX919A uses data bloc...