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DS3171/DS3172/DS3173/DS3174
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3.10 Trail Trace Buffer Features
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Each port has a dedicated Trail Trace Buffer for E3-G.832 link management
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Extraction and storage of the incoming G.832 trail access point identifier in a 16-byte receive register
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Insertion of the outgoing trail access point identifier from a 16-byte transmit register
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Receive trace identifier unstable status indication
3.11 Bit Error Rate Tester (BERT) Features
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Each port has a dedicated BERT tester
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Generation and detection of pseudo-random patterns and repetitive patterns from 1 to 32 bits in length
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Pattern insertion/extraction in DS3/E3 payload or entire data stream to and from the line interface
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Large 24-bit error counter allows testing to proceed for long periods without host intervention
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Errors can be inserted in the generated BERT patterns for diagnostic purposes (single bit errors or specific bit-
error rates)
3.12 Loopback Features
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Analog interface loopback – ALB (transmit to receive)
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Line facility loopback – LLB (receive to transmit) with optional transmission of unframed all-one AIS payload
toward system/trunk interface
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Framer diagnostic loopback – DLB (transmit to receive) with automatic transmission of DS3 AIS or unframed
all-one AIS signal toward line/tributary interface(s)
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DS3/E3 framer payload loopback – PLB (receive to transmit) with optional transmission of unframed all-one
AIS payload toward system/trunk interface
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Simultaneous line facility loopback and framer diagnostic loopback
3.13 Microprocessor Interface Features
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Multiplexed or non-multiplexed address bus modes
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8-bit or 16-bit data bus modes
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Byte swapping option in 16-bit data bus mode
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Read/Write and Data Strobe modes
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Ready handshake output signal
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Global reset input pin
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Global interrupt output pin
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Two programmable I/O pins per port
3.14 Test Features
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Five pin JTAG port
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All functional pins are inout pins in JTAG mode
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Standard JTAG instructions: SAMPLE/PRELOAD, BYPASS, EXTEST, CLAMP, HIGHZ, IDCODE
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RAM BIST on all internal RAM
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Hi-Z pin to force all digital output and inout pins into HIZ
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TEST pin for manufacturing scan test modes