Keyboard Interfacing With 8086 Using 8255 Pdf Download HOT

The simple I/O interfacing method is discussed. The auxiliary parallel I/O circuit and the LED display are installed. The simple I/O method of interfacing calls for all input and output tohappen at specific times in the execution of a program as determined by software and not hardware interrupts. First, the LEDs and limiting resistors are installed. Then the DIP switchesare installed along with the pull up resistors. The LED portion of the circuit is wired to the 74LS240 and the DIP switches are wired to the parallel port A of the 8255. The connections are checked electrically and then the monitor program is used to send configuration information to the 8255 and sample data is inputted and outputted using the switches and LEDs. Figure 8 illustrates the parallel I/O circuit. 2b1af7f3a8