COBHAM GR712RC User Manual

GR712RC-UM, Jun 2017, Version 2.9 155 www.cobham.com/gaisler
GR712RC
21 MIL-STD-1553B BC/RT/BM
21.1 Overview
The 1553 interface provides a complete Mil-Std-1553B Bus Controller (BC), Remote Terminal (RT)
or Monitor Terminal (MT). The interface connects to the MIL-STD-1553B bus through external
transceivers and transformers. The interface is based on the Actel Core1553BRM core version 2.16.
The interface consists of six main blocks: 1553 encoder, 1553B decoders, a protocol controller block,
AMBA bus interface, command word legality interface, and a backend interface.
The interface can be configured to provide all three functions BC, RT and MT or any combination of
the three. All variations use all six blocks except for the command legalization interface, which is
only required on RT functions that implement RT legalization function externally.
A single 1553 encoder takes each word to be transmitted and serializes it using Manchester encoding.
The encoder also includes independent logic to prevent the interface from transmitting for greater
than the allowed period as well as loopback fail logic. The loopback logic monitors the received data
and verifies that the interface has correctly received every word that it transmits. The output of the
encoder is gated with the bus enable signals to select which buses the interface should be transmitting
on. Two decoders take the serial Manchester received data from each bus and extract the received data
words.
The decoder contains a digital phased lock loop (PLL) that generates a recovery clock used to sample
the incoming serial data. The data is then de-serialized and the 16-bit word decoded. The decoder
detects whether a command, status, or data word has been received, and checks that no Manchester
encoding or parity errors occurred in the word.
The protocol controller block handles all the message sequencing and error recovery for all three
operating modes, Bus Controller, Remote Terminal, and Bus Monitor. This is complex state machine
that processes messages based on the message tables setup in memory, or reacts to incoming com-
mand words. The protocol controller implementation varies depending on which functions are imple-
mented. The AMBA interface allows a system processor to access the control registers. It also allows
the processor to directly access the memory connected to the backend interface, this simplifies the
system design.
The interface comprises 33 16-bit registers. Of the 33 registers, 17 are used for control function and
16 for RT command legalization. The core generates interrupt 14.
Figure 67. Block diagram
AMBA AHB
Actel Core1553BRM
CPU IF
MEM IF
AHB slave IF
AHB master IF
Control
registers
1553 signals
B1553BRM
Core1553BRM signals

COBHAM GR712RC Specifications

General

Brand	COBHAM
Model	GR712RC
Category	Computer Hardware
Language	English