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EMBEDDED MULTITASKING

The Easy Way
by Charles Kosina

Start ý An Example ý State Machine Control ý Keyboard Scanning ý Receive Serial Data ý LCD Module ý Transmit Data ý Debugging Techniques ý Other Options ý Sources and PDF

OTHER OPTIONS

I started with the Z180, so I may as well finish with it. Derivatives of the Z180 seem to be the flavor of the month again, and Listing 7 shows how the jump table can be implemented for this processor. Try the same technique for your favorite micro, although youýll find that some of the simpler chips donýt have the addressing modes for this approach.

The example I used in this article is trivial but serves to illustrate the technique. Most applications have 20 or more states in their state machine, but the principles remain the same. Other tasks such as reading I/O ports, getting data from an ADC, or sending data out to a DAC can be easily added as complete blocks. As long as you follow the rules, other tasks that are already debugged should not be affected.

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