Cobham Gaisler AB provides IP cores and supporting development tools for embedded processors based on the SPARC architecture. We specialize in digital hardware design for both commercial and aerospace applications

GR1553B Mil-Std-1553B/AS15531 Interface

GR1553B Block diagram The GR1553B core implements the MIL-STD-1553B (Notice 2) data bus protocol, with ability to serve as Bus Controller (BC), Remote Terminal (RT) or Bus Monitor (BM).

The core is connected to the MIL-STD-1553B bus via a dual transceiver interface (txP/N/en, rxP/N/en). On the system side, the core connects to the AMBA bus as an AHB master for DMA transfers and an APB slave for register access. The core uses a separate 20 MHz clock for the MIL-STD-1553B codec, and runs at any AMBA clock frequency from 10 MHz and upwards.

As Bus Controller, the core works using an automated transfer list concept. The BC supports all permitted transfer types and includes other features such as automatic retries on same or alternating buses, extended RT response timeout for systems with bus repeaters, transfer list looping and branches.

In Remote Terminal mode, the core uses a subaddress table where the user can specify per subaddress whether to accept transmit, receive or broadcast transfers, and maximum transfer size. For storing transfer results and data, linked lists of descriptors are used, with each descriptor pointing to a data

The Bus Monitor can be run by itself or simultaneously while the core is running as RT or BC. It listens to traffic on the bus and logs the words in a ring buffer. The BM can filter traffic to get only the RT address, subaddress or mode codes of interest, and also log parity and Manchester code errors. All entries in the bus monitor log are time stamped.

Features

General

  • Implements the MIL-STD-1553B (Notice 2) and SAE AS15531 data bus
  • All transfer types supported, including RT-to-RT and broadcast transfers
  • Dual-redundant bus support
  • Continuous loop-back checking of transmitted MIL-STD-1553B data
  • AMBA (Rev 2.0) AHB master interface, 16-bit aligned data buffers

Bus Controller

  • Automated transfer list with allocated time slots
  • Synchronized start of transfer list with external pulse
  • Automatic retries on same or alternating buses
  • Secondary transfer list for best-effort, low priority transfers
  • Optional interrupt generation at pre-defined points in transfer list
  • Configurable RT response timeout, up to 44 μs

Remote Terminal

  • Flexible software interface allowing customizable buffering setups
  • Auto wrap-around subaddress capable
  • Time-stamping of transfers
  • Programmable per subaddress maximum transfer size and transmit/receive/broadcast enable
  • Interrupt generation on selected subaddresses
  • Dedicated output that pulses on reception of a synchronize mode code

Bus Monitor

  • Ring buffer log
  • Filter on address, subaddress, mode codes
  • Can run in parallel with BC or RT

  Documentation

Deliverables

  • FPGA/ASIC netlist
  • Stand-alone testbench
  • Optional plug and play interface for GRLIB IP library
  • User's manual
  • Driver for RTEMS and VxWorks

Development boards

Development boards for early development and fast prototyping of systems using the GR1553B core are available, equipped with either Xilinx or Actel FPGA. Each board can be operated either stand-alone or installed as a compact PCI plug-in card.