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