Carrier Band Modem (CBM)

The bipolar LSI MC68194 Carrier Band Modem (CBM) when combined with the MC68824 Token Bus Controller provides an IEEE 802.4 single channel, phase−coherent carrier band Local Area Network (LAN) connection. The CBM performs the Physical Layer function including symbol encoding/decoding, signal transmission and reception, and physical management. Features include:

• Implements IEEE 802.4 single channel, phase−coherent Frequency
   Shift Keying (FSK) physical layer including receiver blanking.
• Provides physical layer management including local loopback mode,
   transmitter enable, and reset.
• Supports data rates from 1 to 10 Mbps. IEEE 802.4 standard uses 5
   or 10 Mbps.
• Interfaces via standard serial interface to MC68824 Token Bus
   Controller.
• Crystal controlled transmit clock.
• Recovery of clocked data through phase−locked loop.
• RC controlled Jabber Inhibit Timer.
• Single +5.0 volt power supply.
• Available in 52−lead Cerquad package.