Analog Devices ADSP-CM403F EZ-KIT Lite, Руководство пользователя

Страница: 43 / 75

ADSP-CM403F EZ-KIT Lite Evaluation System Manual 2-9
ADSP-CM403F EZ-KIT Lite Hardware Reference
Each of the software examples include a source file that programs the soft
switches, even if the default settings are being used. The
README
for each
example identifies only the signals that are being changed from their
default values. The code that programs the soft switches is located in the
SoftConfig_CM408F.c
file in each example.
Table 2-2 outlines the default values for the Microchip MCP23017
device.
The ADSP-CM403F EZ-KIT Lite Schematic shows how the Microchip
GPIO expander (
U27
) is connected to the board’s ICs. All outputs drive
single signal FET switches. The CAN0 and LED1 circuits both use pro-
cessor port pin
PB_15
, and can be selected through SoftConfig. CAN0
enable (
CAN0_EN0
) controls whether the CAN port is enabled or the signals
are connected to the expansion interface. When
CAN0_EN
is low, the CAN
interface is enabled and the processor signals (
PC_00
and
PB_15
) are not
connected to the expansion interface. A
CAN0_EN
setting of high connects
the signals to the expansion interface and disconnects the CAN port. This
is done through the inverter IC (
U3
).
Table 2-3 and Table 2-4 show the output signals of the Microchip GPIO
expander (
U27
), with a TWI address of 0100 001X, where X represents the
read or write bit. The signals that control an individual FET have an entry
under the
FET column. The Component Connected column shows the
board IC that is connected if the FET is enabled. Also note that if a
particular functionality of the processor signal is being used, it will be in
bold font under the Processor Signal column.
Table 2-2. I
2
C Hardware Address 0x40
GPIO MCP23017 Register Address Default Value
GPIOA 0x12 0xE0
GPIOB 0x13 0xC1