PCI 1553 cardThe RTX1553/PCI card is an intelligent MIL-STD 1553 interface card for the PCI bus. The MIL-STD1553 communication protocol is implemented in firmware using an FPGA. The RTX1553/PCI card interfaces with the host CPU via a dual-ported, shared memory, accessible to the host in its address space. The card can be configured as a Bus Controller (BC), a single Remote Terminal (RT) or as multiple (up to 32) RT’s. The card has 1Mbyte of on board memory used for control and data buffering. The RTX1553/PCI comes with an extensive software API library. The RTX1553/PCI card Architecture consists of four main building blocks: (a) The PCI bus interface, (b) The MIL-STD1553 protocol processor, (c) The MIL-STD1553 compatible transceiver and output transformers, (d) 1Mbyte of static RAM organized as 512Kx16. The PCI bus controller is an industry standard chip supporting a 32 bit wide PCI bus at 33MHz. This controller handles all PCI interface tasks including memory address mapping offering ‘plug and play’ capabilities. The MIL-STD1553 protocol processor is implemented in the firmware of a powerful FPGA. The FPGA provides automatic message handling, message status, general status, and interrupt information. The register-based interface architecture provides many programmable functions as well as extensive information pertinent to card maintenance. Incoming 1553 messages are stored in a very high-speed memory on board the FPGA for quick analysis before the data is transferred, by DMA, to the dual ported RAM. Every incoming receive-data command is compared (on the fly) with the data previously received for that RT on that sub-address and a flag is set if they are different. This alleviates redundant message processing by the host computer since typically MIL-1553-STD messages are repeated at a constant rate, often sending the same information over and over again.

Bus Controller Features
The RTX1553/PCI Bus Controller (BC) is a powerful MIL-STD-1553 bus controller developed to meet the requirements of multi-frame processing with low host overhead. User-defined commands enable the BC to operate autonomously from the host until a designated event or series of events has taken place. The RTX1553/PCI BC architecture allows the chaining of multiple MIL STD-1553 commands into major and minor frames depending on the application. This feature allows the host to structure message frames that perform independent tasks such as periodic data transfer, service requests, and bus diagnostics (initiate BIT). The BC uses a simple OpCode scheme to control the command block flow. The BC allows host entry of data to control the time between messages. This feature is useful when the BC has to perform periodic message transactions with multiple remote terminals. The host can instruct the BC to interrogate the status word response of remote terminals to determine if any BC action is required. The BC can detect the assertion of status word bits and branch to a new message frame. Polling is useful if the application requires control of message frame flow as a function of remote terminal response.

Remote Terminal Features
The RTX1553/PCI Remote Terminal (RT) conforms to the requirements of MIL-STD-1553B, Notice II. In addition to meeting the requirements of the standard, the RT has an extensive list of flexible features to meet any MIL-STD-1553 interface requirement. The RT supports a number of advanced buffer management techniques (i.e. ping-pong, or circular buffers) to enhance performance in high traffic applications. Every newly arrived data buffer is time tagged and then compared with the previously arrived buffer for that same RT for that same sub-address. If they differ a tag is set indicating to the host that this buffer requires processing. This simple hardware mechanism may save the host CPU from constantly processing messages that carry no new
information. An internal 256-bit of RAM (for every RT) allows for the illegalization of mode codes and sub addresses. The illegalization RAM is accessed at the beginning of message processing to determine if the valid command is prohibited. The RTX1553/PCI can store all data associated with a broadcast command in separate memory from non-broadcast commands. This feature is user selected via the Descriptor Control word and internal Control Register. The RTX1553/PCI generates a Message Information Word and time-tag (16-bit) for all transacted messages. This information is written into memory along with message data words. The Message Information Word contains word count, message errors, and message type information.

The Software Interface
RTX provides an extensive software API library. The API is fully documented with coding examples and is easy to use. It covers all capabilities of the RTX1553/PCI card and releases the programmer from detailed understanding of the hardware. RTX Systems offers extensive free support to our customers in their application development / integration effort. RTX also offers Navigator1553, an optional graphical user interface (GUI) software for Windows.
Navigator1553 is intuitive and simple to use. It enables a user to set up a BC with a sophisticated transmission schedule, or to easily setup a multiple RT environment.



PCI Card