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
10
SLAU595B – October 2014 – Revised January 2017
Copyright © 2014–2017, Texas Instruments Incorporated
MSP430FR4133 LaunchPad™ Development Kit (MSP
‑
EXP430FR4133)
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 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.
The pathway of the backchannel UART is shown in
. The backchannel UART is the UART on
eUSCI_A0. Because of USCI limitations, this UART channel is shared with the UART on the 20-pin
BoosterPack connector (eUSCI_A0). This UART channel is also shared with the red LED on P1.0. This is
a lot of sharing, but all 64 pins of the device are used and this was done out of necessity. The P1.0 pin
serves more functions than any other.
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 (see
).
Figure 7. Application Backchannel UART in Device Manager
