eZ-FET
Emulator
MCU
Isolation
Jumper Block
S
p
y
-B
i-
W
ir
e
(
S
B
W
)
E
m
u
lati
o
n
A
p
p
li
cati
o
n
U
A
RT
3
.3
V
P
o
w
e
r
5
V
P
o
w
e
r
Target MSP430
MCU
e
Z
-F
ET
MS
P
4
30
T
arg
e
t
USB Connector
in out
LDO
B
o
o
ste
rP
ac
k
H
e
ad
e
r
B
o
o
st
e
rP
ac
k
H
e
ad
e
r
USB
EnergyTrace
Hardware
Figure 6. eZ-FET Isolation Jumper Block Diagram
2.2.4
Application (or "Backchannel") UART
The backchannel UART allows communication with the USB host that is not part of the target application's
main functionality. This is very useful during development, and also provides a communication channel to
the PC host side. This can be used to create graphical user interfaces (GUIs) and other programs on the
PC that communicate with the LaunchPad.
shows the pathway of the backchannel UART. The backchannel UART is the UART on
eUSCI_A1. This UART channel is separate from the UART on the 20-pin BoosterPack connector
(eUSCI_A0).
On the host side, a virtual COM port for the application backchannel UART is generated when the
LaunchPad enumerates on the host. You can use any PC application that interfaces with COM ports,
including terminal applications like Hyperterminal or Docklight, to open this port and communicate with the
target application. You need to identify the COM port for the backchannel. On Windows PCs, Device
Manager can assist.
10
MSP430FR6989 LaunchPad™ Development Kit (MSP
‑
EXP430FR6989)
SLAU627A – May 2015 – Revised July 2015
Copyright © 2015, Texas Instruments Incorporated
