eZ-FET
Debug
Probe
Isolation
Jumper Block
Sp
y-
Bi
-W
ire
(SBW
)
Emu
la
ti
o
n
Ap
p
lica
ti
o
n
U
AR
T
3
.3
-V
Po
w
e
r
5
-V
Po
w
e
r
T
a
rg
e
t
MSP4
3
0
G
2
5
5
3
e
Z-
F
ET
MSP4
3
0
T
a
rg
e
t
USB Connector
in out
LDO
Bo
o
st
e
rPa
ck
H
e
a
d
e
r
Bo
o
st
e
rPa
ck
H
e
a
d
e
r
USB
EnergyTrace
Technology
Hardware
9
SLAU772A – June 2018 – Revised March 2020
Copyright © 2018–2020, Texas Instruments Incorporated
MSP430G2553 LaunchPad™ Development Kit (MSP
‑
EXP430G2ET)
•
To control 3-V and 5-V power flow between the eZ-FET and target domains
•
To expose the target MCU pins for uses other than onboard debugging and application UART
communication
•
To expose the programming and UART interface of the eZ-FET so that it can be used for MCUs other
than the onboard MCU.
Table 2. Isolation Block Connections
Jumper
Description
GND
Ground
5V
5-V VBUS from USB
3V3
3.3-V rail, derived from VBUS in the eZ-FET domain
RXD <<
Backchannel UART: The target G2553 receives data through this signal. The arrows indicate the direction of the signal.
TXD >>
Backchannel UART: The target G2553 sends data through this signal. The arrows indicate the direction of the signal.
SBW RST Spy-Bi-Wire debug: SBWTDIO data signal. This pin also functions as the RST signal (active low).
SBW TST Spy-Bi-Wire debug: SBWTCK clock signal. This pin also functions as the TST signal.
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 main functionality
of the target application. This is useful during development and also provides a communication channel to
the PC host. This communication can be used to create graphical user interfaces (GUIs) and other
programs on the PC that communicate with the LaunchPad development kit.
shows the pathway of the backchannel UART. The backchannel UART is the UART on
USCI_A0.
