Analog Devices ADSP-21992 EZ-KIT LITE, System Manual

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ADSP-21992 EZ-KIT Lite Evaluation System Manual 2-5
Using the EZ-KIT Lite
Using Programmable Flag Pins
The ADSP-21992 DSP has eight asynchronous Programmable Flag (PF)
I/O pins (
PF7–0
) that let you interact with the running program. Data pins
8-15 can also be used as Programmable Flag pins, depending on the configu-
ration of the DSP.
During reset, the flag pins (
PF7–0
) are used to set the multiplication factor,
which sets the core clock frequency. After the DSP is reset, the flags are config-
ured as inputs. The direction of the flags is configured though the
DIR
register
and are set and read though the
FLAGC/S
register. For more information on
configuring the flag pins, see the ADSP-2199x Mixed Signal DSP Controller
Hardware Reference. Flags and their uses are described in
Table 2-2 .
!
All the programmable flags are available on connector
P9
.
Table 2-2. Programmable Flag Pin Summary
Flag Connected To Description
PF0 LED8 PF3–0
are connected to the LEDs. They supply feedback for
program execution. For instance, you can write your code to
trigger a flag (and the corresponding LED) when a routine is
complete.
PF1 LED9
PF2 LED10
PF3 LED11
PF4 SW3
– Push button
PF5–4
are connected to the push buttons on the EZ-KIT
Lite board and are for user input. For instance, you can tell
your program to poll for a flag and when it occurs, do other
operation, such as to jump to another instruction.
PF5 SW2
– Push button
PF6
AD1803 Reset
PF6
is connected to the AD1803 telephony codec reset, and can
be used to put the chip in reset.
PF7
AD1885 Reset
PF7
is connected to the AD1885 audio codec reset, and can be
used to put the chip in reset.