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