The DS21448DK is an easy-to-use evaluation board for the DS21448 quad E1/T1/J1 LIU. It is intended to be used as a daughter card with the DK101 motherboard or the DK2000 motherboard. A surfacemounted DS21448 and careful layout of the analog signal traces provide maximum signal integrity to demonstrate the transmit and receive capabilities of the DS21448. The DK101/DK2000 motherboard and Dallas' ChipView software give point-and-click access to configuration and status registers from a Windows-based PC. On-board LEDs indicate interrupt status and receive-carrier loss for all four ports. The evaluation board provides both RJ45 and BNC connectors for the line-side transmit and receive differential pairs on all four ports.