CT-161-CD Fujitsu Semiconductor America Inc, CT-161-CD Datasheet - Page 69

• Manufacturer Part Number: CT-161-CD
• Description: KIT 16LX FOR MB90F387
• Manufacturer: Fujitsu Semiconductor America Inc
• Series: F²MC-16LXr
• Type: MCUr

Specifications of CT-161-CD

• Contents: Board, Cable, CD
• For Use With/related Products: MB90F387S
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 865-1103

5 “Let's try to control the LED by interrupt.”
© Fujitsu
A method to detect the switch operation state was described in Chapter 3. There are also other
methods to detect switch operation than the one described in Chapter 3. One of the other
methods is to use an external interrupt input.
operation by using an external interrupt input.
5.1
Let's begin with a brief explanation of interrupts. The word "interrupt" is popularly used in
daily life, and the meaning of the word is similar when the word is used in the world of
microcomputers. Imagine that you are studying at home on the day before an examination
day. You need to focus on study but are disturbed by a telephone call from a friend or an
unexpected visitor.
terminology names the events like the telephone call and visitor as "interrupt factors" and the
handling of such events as "interrupt processing." Of course, the interrupts in the world of
microcomputers are not telephone calls and visitors but the on/off operation of a switch,
reception of communication data, generation of a timer event, and other various events typical
for microcomputers.
In the field of microcomputer and embedded system, using interrupts in programs is generally
regarded as an efficient programming method. In the real word, you cannot predict when
you will receive telephone calls and visitors. You cannot focus on study if you have to often
look at the telephone or get the door to check to see if there is a visitor. Therefore, you
usually keep concentrating on study and interrupt it only when you receive a telephone call or
visitor actually; this is more efficient.
The microcomputer is provided with a mechanism that notifies the microcomputer program of
a switch on/off operation, communication data reception, timer event, or the like
What is an interrupt?
The telephone call and visitor are interrupts.
Figure 5.1 Cases of interrupt
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This chapter explains how to detect switch
The microcomputer