ELEC 2220 Homework #16 Due: Wednesday, July 14 The purpose of this exercise is to practice setting up and using an interrupt service routine to process an external “event”. In this case, the “event” will be the pressing of a key on a keyboard. One of the CodeWarrior “components” is the “IT_Keyboard”, described in class. You should also study the example in Chapter 18.2 of the text. This component simulates the operation of a standard matrix keyboard, with 5 rows of 4 keys per row (20 keys total). The exact configuration is shown in the CodeWarrior “help” documentation. The keypad must be connected to two I/O ports to implement a standard keyboard scanning algorithm. The IT_keyboard triggers an interrupt if any key is pressed while the corresponding row line or column is “active” (low). Set up the IT_keyboard component with the columns driven by Port T, the row lines scanned (read) through Port AD, and with the keyboard triggering an IRQ interrupt (“vector” number 6 in the keyboard setup window).
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