Analog Devices ADSP-2189M EZ-KIT Lite, Manual

Page: 28 / 81

Standard Operations
2-4 ADSP-2189M EZ-KIT Lite Evaluation System Manual
Input and Output Devices
The board’s IO component are detailed in the following sections.
• “Flags” on page 2-4
• “Interrupts” on page 2-4
• “Serial Ports” on page 2-5
Flags
The ADSP-2189M processor has one asynchronous
FLAG
IO pin,
FL1
. The
pin is connected to the amber
FL1
LED. This lets you visually inspect
states of your program. The other nine programmable flags (PFs) connect
to the expansion area.
Interrupts
The ADSP-2189M EZ-KIT Lite has one external interrupt connected
through a push button switch,
SW1
. This corresponds to an external inter-
rupt,
IRQE
.
The external interrupts are controlled through the
ICNTL
and
IMASK
regis-
ters and are configured by modifying the interrupt vector table or through
instructions in user code. The
ICNTL
register also controls the interrupt
sensitivity between level and edge. To prevent an interrupt from being
masked, write to the
IMASK
register.
The monitor program running on the ADSP-2189M processor uses one
interrupt (
Timer
) for normal operation. When downloading your own
code through the monitor program, the timer interrupt vector is protected
and cannot be overwritten. If these vectors are overwritten, or the timer