Texas Instruments MSP-EXP430F5529LP 사용자 설명서
Hardware
2.5
Using the eZ-FET lite Emulator With a Different Target
The eZ-FET lite emulator on the F5529 LaunchPad can interface to most MSP430 derivative devices, not
just the on-board F5529 target device.
just the on-board F5529 target device.
To do this, disconnect every jumper in the isolation jumper block. This is necessary because the emulator
cannot connect to more than one target at a time over the Spy-Bi-Wire (SBW) connection.
cannot connect to more than one target at a time over the Spy-Bi-Wire (SBW) connection.
Next, make sure the target board has proper connections for Spy-Bi-Wire. Note that to be compatible with
SBW, the capacitor on RST/SBWTDIO cannot be greater than 2.2 nF. The documentation for designing
MSP430 JTAG interface circuitry is the MSP430 Hardware Tools User's Guide (
SBW, the capacitor on RST/SBWTDIO cannot be greater than 2.2 nF. The documentation for designing
MSP430 JTAG interface circuitry is the MSP430 Hardware Tools User's Guide (
).
Finally, wire together these signals from the emulator's side of the isolation jumper block to the target
hardware:
hardware:
•
3.3 V
•
GND
•
5 V (if needed)
•
SBWTDIO
•
SBWTCK
•
TXD (if the UART backchannel is to be used)
•
RXD (if the UART backchannel is to be used)
•
CTS (if hardware flow control is to be used)
•
RTS (if hardware flow control is to be used)
This wiring can be done either with jumper wires or by designing the board with a connector that plugs into
the isolation jumper block.
the isolation jumper block.
2.6
USB BSL Button
Like the vast majority of MSP430 derivatives, the F5529 has an on-chip bootstrap loader (BSL). The BSL
is a program that resides in a special protected location in the MCU's flash memory and facilitates
communication with an external host. Like tools with JTAG access, it can read and write the MCU's flash
memory. But unlike JTAG tools, it cannot be used to emulate code.
is a program that resides in a special protected location in the MCU's flash memory and facilitates
communication with an external host. Like tools with JTAG access, it can read and write the MCU's flash
memory. But unlike JTAG tools, it cannot be used to emulate code.
The interface to the BSL is often a UART or sometimes I2C. On USB-equipped derivatives, the BSL's
interface is USB.
interface is USB.
In situations where JTAG access is not available, the BSL plays an important role in accessing the device.
For example, it can be used to recover the device when something has corrupted internal flash. It is often
used for products in the field, when there is no JTAG access. Because of the use in the field, the BSL is
password-protected, which prevents unwanted access to proprietary application software. To serve its role
in updating MSP430 flash memory, the BSL must be invoked, meaning that execution must be transferred
to it. This can happen a few different ways, but on the USB BSL, one way is to pull the PUR pin high
immediately after a BOR reset.
For example, it can be used to recover the device when something has corrupted internal flash. It is often
used for products in the field, when there is no JTAG access. Because of the use in the field, the BSL is
password-protected, which prevents unwanted access to proprietary application software. To serve its role
in updating MSP430 flash memory, the BSL must be invoked, meaning that execution must be transferred
to it. This can happen a few different ways, but on the USB BSL, one way is to pull the PUR pin high
immediately after a BOR reset.
The USB BSL button on the F5529 LaunchPad (see
) serves this purpose.
Figure 21. USB BSL Button
25
SLAU533A – September 2013 – Revised January 2014
MSP430F5529 LaunchPad™ Development Tool (MSP
‑
EXP430F5529LP)
Copyright © 2013–2014, Texas Instruments Incorporated