Application Examples
OVERVIEW
The following examples show simple uses of some of the more
complex devices on the ZT 8809A board. Each example is described
first by an outline of the objectives, followed by the software in
outline form.
The first example is divided into two parts: the first part shows the
use of the programmable interrupt controller and the minimum steps
required to handle one interrupt from the on-board timer; the second
part shows the use of the ZT 8809A with an external interrupt
controller on the ZT 8840 Quad UART board used as a slave to the
ZT 8809A interrupt controller.
The second example uses one of the counter/timers as a watchdog
timer, which is generally done to ensure that the board is operating
properly and is not lost. The third example shows how to use the real-
time clock when STD DOS is not present on the board to manage it.
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