DS31256

The Analog Devices DS31256 Envoy is a high-performance 256-channel HDLC controller capable of handling up to 60 T1 or 64 E1 data streams, or two T3 data streams. Each of its 16 physical ports can be independently configured for channelized or unchannelized operation, supporting one, two, or four T1 or E1 lines per port in channelized mode. The controller offers up to 132Mbps full-duplex throughput, with three dedicated fast HDLC engines capable of operating at speeds up to 52Mbps, while other ports support up to 10Mbps in unchannelized mode.

Key features include per-channel DS0 loopbacks, on-board BERT with automatic error insertion, large 16kB FIFOs, and efficient scatter/gather DMA. The DS31256 integrates Layer 1, HDLC processing, FIFO, DMA, and a PCI bus interface (33MHz 32-Bit PCI V2.1). It operates from a 3V to 3.6V supply with 5V tolerant I/O and is housed in a 256-pin Plastic Ball Grid Array (PBGA) package measuring 27mm x 27mm. The device is suitable for applications such as T1/E1/T3/E3 routers, high-density Frame-Relay access, xDSL multiplexers, and SONET/SDH equipment.

This controller operates within a temperature range of 0°C to 70°C. It supports Intel or Motorola bus signals and includes JTAG support (IEEE 1149.1). The DS31256 is designed for surface mount applications and is backward compatible with the DS3134.