The Bt8954 framer has been tailored specifically to meet the needs of voice pair gain systems (also referred to as “cable relief systems” and “digital subscriber line carriers”) by providing a direct connection to the DSL modem and the CODEC.

Distinguishing Features
• Voice Pair Gain Framer
    – Frames and transports PCM data streams over 12–18,000 ft. (3.7–5.5 km) distances when coupled with Bt8960 or Bt8970
• PCM Interface
    – Supports popular PCM codecs
    – Programmable payload to support 2–18 64 kbps voice channels
    – 2.048, 1.536 MHz PCM reference clock generation
    – 6.144, 8.192, 20.48 MHz ADPCM reference clock generation
• DSL Interface
    – Connects to Bt8960 or Bt8970
    – Supports 160–1168 kbps bit rates
    – Error performance monitoring
    – Auto tip/ring reversal
• Microcomputer Interface
    – Glueless interface to Intel 8051 and Motorola 68302 processors
    – Access to overhead and signaling registers
• Supports ADPCM codecs (32 kbps)
• PCM and DSL loopbacks
• CMOS technology, 5 V operation
• Low-power operation
    – Enables compatibility with line-powered systems
• 68-pin PLCC
• JTAG/IEEE Std 1149.1-1990
• –40 °C to +85 °C operation

Applications
• Voice Pair Gain Systems (Clear)
    – PCM2, PCM4(PCM1+3), PCM6,
    – PCM8, PCM10/11, PCM12, PCM18
• ADPCM Voice Pair Gain Systems (Compressed)
    – ADPCM12, ADPCM24, ADPCM36