Texas Instruments SWRU294, Руководство пользователя, Страница: 13 / 57

SWRU294
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Hold MSP430 &
EM in reset
Forced recovery or
no/invalid application
Release MSP430
& EM reset
Recovery Mode Launch application
No
Determine operating
mode (S1/S2)
SmartRF Mode
Release EM
reset
Release MSP430
& EM reset
UART Mode Disabled Mode
Power-on-Reset
Enable Cebal
USB interface
Yes
USB MCU Standard Application
USB MCU Bootloader
Enable Cebal
USB interface
Release MSP430
& EM reset
Enable CDC-ACM
USB interface
S1/S2 change
Enter low-power
mode
SmartRF
UART
Disabled
Figure 4
– Flow chart of the USB MCU bootloader and standard firmware
When the bootloader starts running, it will check for a valid application in the CC2511 flash
memory. If detection is successful, the application is started and the board can be operated
normally. If no application is detected (e.g. blank flash or firmware upgrade failed) the USB LED
(D6) will start blinking rapidly
– indicating failure. See section 6.9.2 for more details on USB LED
states.
The USB MCU bootloader will allow programming/upgrading of the USB MCU firmware over the
USB interface. No additional hardware or programmers are needed. Both SmartRF Studio and
SmartRF Flash Programmer [4] can be used for this purpose. Please refer to chapter 11 for
details.
The standard firmware application has three operating modes, controlled by hardware switches
S1 and S2. The three modes
are named “SmartRF Mode”, “UART Mode” and “Disabled Mode”.
Table 4 shows which S1 and S2 positions that give the different operation modes. The following
sections will discuss the different operating modes in more detail.