Analog Devices ADSP-21479 EZ-Board, Руководство пользователя

Страница: 36 / 113

SPI Interface
1-16 ADSP-21479 EZ-Board Evaluation System Manual
By default, the EZ-Board boots from the 8-bit parallel flash memory. The
processor boots from flash memory if the boot mode select switch (
SW4
) is
set to position 2; see “Boot Mode Select Switch (SW4)” on page 2-10 .
Flash memory code can be modified. For instructions, refer to the online
help and example program included in the EZ-Board installation
directory.
For more information about the parallel flash device, refer to the
Numonyx Web site:
http://www.numonyx.com
.
SPI Interface
The ADSP-21479 processor has two SPI ports, which can be accessed via
the digital peripheral interface (DPI) pins.
The SPI flash memory, a 16 Mb ST M25P16 device, connects to the SPI
port of the processor and designates:
• DPI pin 5 (
DPI_P5
) as a chip select
• DPI pin 3 (
DPI_P3
) as the SPI clock
• DPI pin 1 (
DPI_P1
) as the master out slave in (
MOSI
) pin
• DPI pin 2 (
DPI_P2
) as the master in slave out (
MISO
) pin
The same SPI port and DPI pins are connected to the serial flash memory
and audio codec via switch
SW3
. See “DPI [1–8] Enable Switch (SW3)” on
page 2-9 . The DPI pins also are available on the expansion interface II.
By default, the EZ-Board boots from the 8-bit flash parallel memory. SPI
flash can be selected as the boot source by setting the boot mode select
switch (
SW4
) to position 1. See “Boot Mode Select Switch (SW4)” on
page 2-10 .