Analog Devices SHARC ADSP-21375, Руководство пользователя

Страница: 53 / 89

ADSP-21375 EZ-KIT Lite Evaluation System Manual 2-17
ADSP-21375 EZ-KIT Lite Hardware Reference
Push Buttons (SW8–11)
Four push buttons (
SW8–11
) are provided for general-purpose user input:
two push buttons connect to the
FLAG
pins of the processor, while the
other two connect to the DAI of the processor. The push buttons are
active high and, when pressed, send a high (
1
) to the processor. Refer to
“LEDs and Push Buttons” on page 1-11 for more information. The push
button enable switch (
SW7
) is capable of disconnecting the push buttons
from the corresponding processor pins (refer to “Push Button Enable
Switch (SW7)” on page 2-13 for more information).
The push buttons and corresponding processor signals are summarized in
Table 2-9 .
Board Reset Push Button (SW12)
The
RESET
push button (
SW12
) resets all of the ICs on the board. The only
exception is the USB interface chips. These chips are not being reset when
the push button is pressed after the USB cable has been plugged in and
communication correctly initialized with the PC. After USB communica-
tion has been initialized, the only way to reset the USB is by powering
down the board.
Table 2-9. Push Button Connections
Push Button Label Push Button Reference Designator Processor Pin
PB1 SW8 FLAG1/~IRQ1
PB2 SW11 FLAG0/~IRQ0
PB3 SW10 DAI19
PB4 SW9 DAI20