Laird Sterling-EWB, Руководство пользователя

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Note: The development board connects the VBAT pin directly to 3V3_MCU. An external battery voltage can be applied to
the EWB module by cutting SB1 to remove the connection to 3V3_MCU and applying a battery voltage to J22
(
Figure 5 ).
The VBAT pin powers the battery power (RTC and backup registers) domain only when VDD is not present.
Figure 5: External VBAT power connector
The development board Module Reset button (SW4) connects directly to the EWB MICRO_RSTN pin and enables manual
reset of the module MCU when pressed.
The micro-USB connector J24 is used in conjunction with a FTDI FT2232H multipurpose USB UART/FIFO IC on the
development board to provide JTAG programming and UART1 serial port access to the STM32F412 MCU on the EWB
module.
The FT2232H has an external EEPROM which is pre-programmed with the custom VID (0x0A5C) and PID (0x43FA) to enable
the USB port to interface with the Cypress WICED® software development kit as well as provide a COM port for monitoring
the debug output of the Laird Sterling-EWB demo application.
The EWB development board boot option is configured by setting SW5 and SW6 ( Figure 6 ).
Figure 6: BOOT configuration switches
Table 1: EWB boot source configuration
SW5 (BOOT 0)
position
SW5 (BOOT 1)
position
Boot Source
0 0 or 1 EWB Module boots from embedded User Flash (Default Setting)
1 1 EWB Module boots from Embedded SRAM
1 0 EWB Module boots from System Memory
The development board contains SPST DIP switches (SW9
– SW12) placed in-line with the EWB module I/O lines that
connect to peripheral devices on the board. This functionality is provided to maximize flexibility, allowing the user to disconnect
any EWB module I/O used by the development board, re-assign their functionality, and use them for development purposes.