Software interrupt as some people may call it. Once we know the IRQ the next step is to find it's interrupt vector or IRQ's 3 and 4 are the two most commonly used. Table 13 shows the base addresses and IRQ's of some The first step to using interrupts is to work out which interrupt services Least upset to other programs which may also be trying to use the communications ports. They all can be restored before you quit the program. Upon executing your communications program, it would be wise to store the
Serials 2k database how to#
The source code above is not a really good example on how to program but is rather cutĭown to size giving quick results, and making it easier to understand. Programmable Interrupt Controller you can find out your IRQ, You don'tīuff1024.c - Simple Terminal Program using Interrupt Requests. Routines for the common IRQs and by enabling one IRQ at a time using the Once you know this information, then you can set up the Interrupt IRQ you are using you can poll the UART at several different addresses toįirstly find which port your card is at and which one your modem is attached If you have no idea of what address your card is at or what Polling the UART should not be dismissed totally. Termpoll.c - Simple Terminal Program using the Polling Method. It will very easily support 115.2K BPS, even The other option is using a Interrupt handler, and
Some newer Pentium Pro's may be able to achieveīetter rates that this. Intensive thus can only have a maximum speed of around 34.8 KBPS before
Polling the UART is a lot slower method, which is very CPU You can poll the UART, to see if any new data is available or you can set upĪn interrupt handler to remove the data from the UART when it generates a When writing a communications program you have two methods available to you. Part 4 : External Hardware - Interfacing Methods Source Code - Termpoll.c (Polling Version)ĭetermining the type of UART via Software First In / First Out Control Register (FCR)
0 kommentar(er)
