Using Interrupts on the IBM PC to Generate Major and Minor Frame Times 872485
The IBM PC and compatibles are being used more and more for 1553 applications. One reason is their availability and low cost. Ruggedized and portable versions, which are available from many manufacturers, allow them to be easily used as suitcase type testers and field portable units. As a result, many companies are now using the PC as the host for their real time 1553 activities.
The BUS-65515 card from ILC Data Device Corporation is a single, memory mapped card which allows the IBM PC, PC/XT, PC/AT and compatibles to be used as a real time 1553 interface. The board allows the PC to act as either a Bus Controller (BC), Remote Terminal (RT) or passive Bus Monitor (MT). Since the card is memory mapped into the PC's address space, the entire 1553 interface looks like RAM to the user's application program. Normal Read/Write statements can be used to access the board - no specialized device driver is required.
The card allows the user to take advantage of many of the PC's built in features. For instance, in many applications, 1553 messages are issued periodically, in bursts known as major and minor frames. This paper will discuss various methods of generating these frames using features available on the IBM PC, and the BOS-65515 card from ILC Data Device Corporation.