The MK53761 is a Silicon Gate CMOS IC that provides necessary signals for either DTMF or loop disconnect (pulse) dialing. The MK53761 buffers up to 18 digits into memory that can be later redialed with a single key input. Up to nine repertory numbers may be stored. Users can store all 12 signaling keys and access several unique functions with single key entries. These functions include : Last Number Dialed (LND), Softswitch, and Flash. Figure 2 shows the keypad configuration.