The M-986-1R2 and -2R2 MFC Transceivers contain all the logic necessary to transmit and receive CCITT R2F (forward) and R2B (backward) multifrequency signals on one 40-pin integrated circuit (IC). M-9861R2 is a single-channel version; M-986-2R2 provides two channels. R1 single and dual multifrequency transceivers are also available as M-986-1R1 and 2R1. Operating with a 20.48 MHz crystal, the M-986 is capable of providing a direct digital interface to an Alaw-encoded PCM digital input. Each channel can be connected to an analog source using a coder-decoder (codec) as shown in the Block Diagram below. The M-986 can be configured by the customer to operate with the transmitter and receiver either coupled together or independently, allowing it to handle a compelled cycle automatically or via command from the host processor. For the R2 versions of the M-986, A-law is used for coding/decoding. The M-986 is configured and controlled through an integral coprocessor port.