The MX828 is a low power SelCall, CTCSS, and DCS signal processor designed for use in the latest generation of LMR (Land Mobile Radio) equipment where sub-audible signaling is required for functions such as Trunking Control, Selective Calling, and Group Calling applications. The MX828 is full duplex and offers many advanced features to assist in the design of new Sub-Audible and in-band based systems. These include: a programmable tone decoder which may be set to respond to between 1 and 15 CTCSS or SelCall tones with minimum software intervention, a Fast/Predictive CTCSS detector that can respond to a single programmed tone in less than 60ms or provide an output if CTCSS tone is present at the detector input, two high resolution tone encoders that accurately generate CTCSS or SelCall tones, and a full 23/24 bit DCS encoder and decoder. The MX828 also provides a general purpose timer, a comparator with a programmable threshold, and a summing amplifier with two adjustable gain blocks to facilitate design integration and reduce part count. The MX828 may be used with a 3.0 to 5.5 volt supply and is available in the following packages: 24-pin SSOP (MX828DS), 24-pin SOIC (MX828DW), and 24-pin PDIP (MX828P). 1997 MXCOM Inc.