Texas Instruments CC3235MODSF SimpleLink User manual

CC3235MODSF SimpleLink™ Wi-Fi® and
IoT Solution With MCU LaunchPad™
Hardware
User’s Guide
Literature Number: SWRU548C
FEBRUARY 2019 – REVISED SEPTEMBER 2021

1 Introduction.............................................................................................................................................................................7
1.1 CC3235MODSF LaunchPad™.......................................................................................................................................... 7
1.2 LAUNCHCC3235MOD Key Features................................................................................................................................ 8
1.3 What's Included..................................................................................................................................................................8
1.4 REACH Compliance...........................................................................................................................................................8
1.5 Regulatory Compliance......................................................................................................................................................8
1.6 First Steps: Out-of-Box Experience....................................................................................................................................9
1.7 Next Steps: Looking into the Provided Code..................................................................................................................... 9
1.8 Trademarks........................................................................................................................................................................ 9
2 Hardware................................................................................................................................................................................11
2.1 Block Diagram..................................................................................................................................................................12
2.2 Hardware Features.......................................................................................................................................................... 14
2.3 Electrical Characteristics..................................................................................................................................................27
2.4 Antenna Characteristics................................................................................................................................................... 27
2.5 BoosterPack Plug-in Module Pinout.................................................................................................................................28
3 Layout Guidelines.................................................................................................................................................................31
3.1 LAUNCHCC3235MOD Board Layout.............................................................................................................................. 31
3.2 General Layout Recommendations..................................................................................................................................36
3.3 RF Layout Recommendations..........................................................................................................................................36
3.4 Antenna Placement and Routing..................................................................................................................................... 38
3.5 Transmission Line Considerations................................................................................................................................... 38
4 Operational Setup and Testing............................................................................................................................................41
4.1 Measuring the CC3235MOD Current Draw..................................................................................................................... 42
4.2 RF Connections............................................................................................................................................................... 44
4.3 Design Files..................................................................................................................................................................... 45
4.4 Software........................................................................................................................................................................... 45
5 Development Environment Requirements......................................................................................................................... 47
5.1 CCS..................................................................................................................................................................................47
5.2 IAR................................................................................................................................................................................... 47
6 Additional Resources...........................................................................................................................................................49
6.1 CC3235MODx Product Page........................................................................................................................................... 49
6.2 Download CCS or IAR..................................................................................................................................................... 49
6.3 SimpleLink™ Academy for CC3235 SDK........................................................................................................................ 49
6.4 TI E2E™ Support Forums.................................................................................................................................................50
7 Assembly Drawing and Schematics................................................................................................................................... 51
7.1 Assembly Drawing........................................................................................................................................................... 51
7.2 Schematics.......................................................................................................................................................................52
A Manual Information to the End User...................................................................................................................................57
A.1 End User Manual............................................................................................................................................................. 57
A.2 RF Function and Frequency Range.................................................................................................................................57
A.3 FCC and IC Certification and Statement......................................................................................................................... 57
A.4 EU Certification and Statement....................................................................................................................................... 60
A.5 CC3235MODx Approved Antennas.................................................................................................................................61
Revision History.......................................................................................................................................................................62
Table of Contents
www.ti.com Table of Contents
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
3
Copyright © 2021 Texas Instruments Incorporated

Table of Contents www.ti.com
4CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
Copyright © 2021 Texas Instruments Incorporated
This page intentionally left blank.

Start your design with the industry's first programmable FCC, IC/ISED, ETSI/CE, MIC, and SRRC 1Certified
SimpleLinkTM Wi-Fi® CC3235MOD Dual-Band Wireless Microcontroller Module with built-in Dual-Band (2.4 GHz
and 5 GHz) Wi-Fi® connectivity. Created for the Internet-of-Things (IoT), the SimpleLink™ CC3235MODx and
CC3235MODAx family of devices from Texas Instruments are wireless modules that integrate two physically
separated, on-chip MCUs:
• An application processor – Arm® Cortex®-M4 MCU with a user-dedicated 256KB of RAM and an optional
1MB of serial flash.
• A network processor MCU to run all Wi-Fi and Internet logic layers. This ROM based subsystem includes an
802.11 a/b/g/n radio, baseband, and MAC with a powerful crypto engine for fast, secure internet connections
with 256-bit encryption.
The CC3235MODx and CC3235MODAx have four total variants:
• CC3235MODSM2MOB
– Requires an external antenna
• CC3235MODSF12MOB
– Requires an external antenna
– Contains 1MB of serial flash
• CC3235MODASM2MON
– Contains an integral antenna
• CC3235MODASF12MON
– Contains an integral antenna
– Contains 1MB of serial flash
The LAUNCHCC3235MOD is a low-cost evaluation platform for MCUs based on Arm® Cortex®-M4 devices.
The LaunchPad™ design highlights the CC3235MODSF fully-integrated industrial module solution and Dual-
Band Wi-Fi capabilities. The LAUNCHCC3235MOD also features temperature and accelerometer sensors,
programmable user buttons, an RGB LED for custom applications, and onboard emulation for debugging. The
stackable headers interface demonstrates how easy it is to expand the functionality of the LaunchPad when
interfacing with other peripherals on existing BoosterPack™ add-on boards, such as graphical displays, audio
codec, antenna selection, environmental sensing, and more.
Figure 1-1 shows the CC3235MODSF LaunchPad development kit.
CC3235MODSF LaunchPad™ Development Kit
(LAUNCHCC3235MOD)
1Contact TI for more information on using SRRC ID Certification: www.ti.com/tool/SIMPLELINK-CC3XXX-CERTIFICATION
www.ti.com CC3235MODSF LaunchPad™ Development Kit (LAUNCHCC3235MOD)
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
5
Copyright © 2021 Texas Instruments Incorporated

Figure 1-1. CC3235MODSF SimpleLink™ Wi-Fi® LaunchPad™ Development Kit
CC3235MODSF LaunchPad™ Development Kit (LAUNCHCC3235MOD) www.ti.com
6CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
Copyright © 2021 Texas Instruments Incorporated

1.1 CC3235MODSF LaunchPad™
Created for the Internet of Things (IoT), the SimpleLink CC3235MODx is a wireless module with built-in Dual-
Band Wi-Fi connectivity for the LaunchPad ecosystem, which integrates a high-performance Arm® Cortex®-M4
MCU and lets customers develop an entire application with one device. With on-chip Wi-Fi, Internet, and robust
security protocols, no prior Wi-Fi experience is required for fast development.
The CC3235MODSF LaunchPad, referred to by its part number LAUNCHCC3235MOD, is a low-cost evaluation
platform for Arm® Cortex®-M4-based MCUs. The LaunchPad design highlights the CC3235MODSF Internet-on-
a chip solution and Dual-Band Wi-Fi capabilities. The CC3235MODSF LaunchPad also features temperature
and accelerometer sensors, programmable user buttons, an RGB LED for custom applications, and onboard
emulation for debugging. The stackable headers of the CC3235MODSF LaunchPad XL interface demonstrate
how easy it is to expand the functionality of the LaunchPad when interfacing with other peripherals on
many existing BoosterPack add-on boards, such as graphical displays, audio codecs, antenna selection,
environmental sensing, and more. Figure 1-1 shows the CC3235MOD LaunchPad.
Multiple development environment tools are also available, including TI’s Eclipse-based Code Composer
Studio™ (CCS) integrated development environment (IDE) and IAR Embedded Workbench®. More information
about the LaunchPad, the supported BoosterPack modules, and the available resources can be found at TI’s
LaunchPad portal.
Note
The maximum RF power transmitted in each WLAN 2.4 GHz band is 19 dBm (EIRP power).
The maximum RF power transmitted in each WLAN 5 GHz band is 18.8 dBm (EIRP power).
Note
The antennas used for this transmitter must be installed to provide a separation distance of at least 20
cm from all persons, and must not be collocated or operating in conjunction with any other antenna or
transmitter.
Chapter 1
Introduction
www.ti.com Introduction
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
7
Copyright © 2021 Texas Instruments Incorporated

1.2 LAUNCHCC3235MOD Key Features
The LAUNCHCC3235MOD SimpleLink LaunchPad includes the following features:
• CC3235MODSF, SimpleLinkTM Dual-Band Wi-Fi® module solution
– Integrated MCU
– 40.0-MHz crystal
– 32.768-kHz crystal (RTC)
– 32-Mbit SPI serial flash
– RF and full power-management components
• 40-pin LaunchPad kit standard that leverages the BoosterPack ecosystem
• TI standard, XDS110-based JTAG emulation with serial port for flash programming
• Supports 4-wire JTAG and 2-wire SWD
• Two buttons and one RGB LED for user interaction
• Back-channel universal asynchronous receiver/transmitter (UART) through USB to PC
• Onboard chip antenna with U.FL for conducted testing selectable using 0-Ω resistors
• Onboard accelerometer and temperature sensor for out-of-box demo with option to isolate the sensors from
the inter-integrated circuit (I2C) bus
• Micro-USB connector for power and debug connections
• Headers for current measurement and external JTAG connection (option to use the onboard XDS110 to
debug customer platforms)
• Bus-powered device with no external power required for Wi-Fi
• Long-range transmission with highly optimized antenna (200 m typical in open air using an access point with
6-dBi antenna AP)
• Can be powered externally, with two AA or two AAA alkaline batteries working down to 2.3-V typical
• Dimensions: 106.1 mm (L) × 58.42 mm (W)
1.3 What's Included
1.3.1 Kit Contents
• CC3235MODSF LaunchPad development kit (LAUNCHCC3235MOD)
• Micro USB cable
• Quick start guide
1.3.2 Software Examples
• Out-of-box experience (OOBE) software
1.4 REACH Compliance
In compliance with the Article 33 provision of the EU REACH regulation we are notifying you that this EVM
includes component(s) containing at least one Substance of Very High Concern (SVHC) above 0.1%. These
uses from Texas Instruments do not exceed 1 ton per year. The SVHCs are:
Component
Manufacturer Component Type Component Part Number SVHC Substance SVHC CAS (When Available)
Abracon Crystal ABM3-16.000MHZ-D2Y-T Diboron Trioxide 1303-86-2
Abracon Crystal ABM3-16.000MHZ-D2Y-T Lead Oxide 1317-36-8
1.5 Regulatory Compliance
The SimpleLink CC3235MODx Wi-Fi LaunchPad kits are tested for and found to be in compliance with FCC and
ISED regulations regarding unlicensed intentional radiators. Hereby, Texas Instruments Inc. declares that the
radio equipment type LAUNCHCC3235MOD are in compliance with Directive 2014/53/EU. The full text of the EU
declaration of conformity is available at the following internet address:
•LAUNCHCC3235MOD Certification of Documents
•LAUNCHCC3235MOD Declaration of Conformity
Introduction www.ti.com
8CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
Copyright © 2021 Texas Instruments Incorporated

Indoor Usage Restrictions
The device is restricted to indoor use only when operating in the 5150- to 5350-MHz frequency range.
AT BE BG HR CY CZ DK
EE FI FR DE EL HU IE
IT LV LT LU MT NL PL
PT RO SK SI ES SE UK
1.6 First Steps: Out-of-Box Experience
An easy way to get started with the EVM is by using its preprogrammed out-of-box experience code. It
demonstrates some key features of the EVM.
1.6.1 Connecting to the Computer
Connect the LaunchPad development kit by connecting the included USB cable to a computer. A red power LED
should illuminate. For proper operation, the SimpleLink drivers and Service Pack from the CC3235 Software
Development Kit (SDK) are needed. The SDK is available at http://www.ti.com/tool/simplelink-cc32xx-sdk.
1.6.2 Running the Out-of-Box Experience
The CC3235MODSF LaunchPad development kit's Out-of-Box Experience (OOBE) demonstrates and highlights
the following features:
• Easy connection to the CC3235MODSF LaunchPad:
– Using the SimpleLinkTM Wi-Fi® Starter Pro application (available on iOS and Android™), users can use
Access Point (AP) provisioning or SmartConfig™ provisioning for a fast CC3235MOD connection.
– Configuring the device in AP mode gives users a direct connection to the CC3235MODSF LaunchPad.
Once the device is provisioned and connected to an AP in station mode, the profile is stored on the local file
system so that any reset to the CC3235MODSF automatically connects it to the AP.
• Easy access to the CC3235MODSF through its internal web server, using either:
– The SimpleLinkTM Wi-Fi® Starter Pro application
– Any browser; web pages stored on the serial flash are loaded on the browser, to provide ease of use.
This feature demonstrates configuring and reading onboard sensors.
• Over-The-Air (OTA) updates that demonstrate an update of a full image. OTA service enables in-system
updates of the MCU application, CC3235 firmware releases (Service Pack) made available by TI, and other
vendor files. An update procedure executed in a full-system integrity fashion, such as failure to upgrade any
image components, results in rolling back to the previous valid version.
Visit the CC3235 LaunchPad Out-of-Box Experience Guide on SimpleLink Academy (see Section 6.3) for more
details.
1.7 Next Steps: Looking into the Provided Code
After the EVM features have been explored, the user can open an integrated development environment and start
editing the code examples from the SDK. See Section 6.2 for available IDEs and where to download them. The
Out-of-Box source code and more code examples are provided in the CC3235 SDK. Code is licensed under
BSD, and TI encourages reuse and modifications to fit specific needs.
With the onboard XDS110 debug probe, debugging and downloading new code is simple. A USB connection
between the EVM and a PC through the provided USB cable is all that is needed.
1.8 Trademarks
E2E™, SimpleLink™, LaunchPad™, BoosterPack™, Code Composer Studio™, and are trademarks of Texas
Instruments.
WPA™ and WPA2™ are trademarks of Wi-Fi Alliance.
Wi-Fi® and Wi-Fi Direct® are registered trademarks of Wi-Fi Alliance.
Arm® and Cortex® are registered trademarks of Arm Limited.
www.ti.com Introduction
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
9
Copyright © 2021 Texas Instruments Incorporated

IAR Embedded Workbench® is a registered trademark of IAR Systems AB.
All trademarks are the property of their respective owners.
Introduction www.ti.com
10 CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
Copyright © 2021 Texas Instruments Incorporated

Figure 2-1 shows the CC3235MODSF LaunchPad EVM.
Figure 2-1. CC3235MODSF LaunchPad™ EVM Overview
Chapter 2
Hardware
www.ti.com Hardware
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
11
Copyright © 2021 Texas Instruments Incorporated

2.1 Block Diagram
Figure 2-2 shows a functional block diagram of the CC3235MODx module.
CC3235
MAC/PHY
WRF_BGN F
BGN
RF_ABG
32-Mbit
SFlash
External SPI
Programming
40 MHz
32.768 kHz
UART
SPI
nReset
PM
2.3 V to 3.6 V
VBAT
User GPIOx
Aband
F
D
5 GHz
SPDT
WRF_A
Figure 2-2. CC3235MODx Functional Block Diagram
Hardware www.ti.com
12 CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
Copyright © 2021 Texas Instruments Incorporated

Figure 2-3 shows a functional block diagram of the LAUNCHCC3235MOD SimpleLink LaunchPad.
CC3235MODSF12MOBR
Acc
BMA280
Temperature
Sensor
TMP116
Two 20-pin LaunchPad headers
(compatible with TI MCU standard)
INT (GPIO13)
I2C
FTDI
FT2232D
and
SWD Circuit
USB
Connector
LDO
3.3 V
VCC
Two AA
Battery
Connectors
Reverse
Protection
Push buttons
GPIO13, GPIO22
RGB LED
GPIO9, GPIO10, GPIO11
JTAG and SWD
UART (Flashing)
Figure 2-3. LAUNCHCC3235MOD Functional Block Diagram
www.ti.com Hardware
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
13
Copyright © 2021 Texas Instruments Incorporated

2.2 Hardware Features
• CC3235MODSF, SimpleLinkTM Dual-Band Wi-Fi® module solution with integrated MCU
• 40-pin LaunchPad™ standard that leverages the BoosterPack™ ecosystem
• TI Standard XDS110-based JTAG emulation with serial port for flash programming
• Supports both 4-wire JTAG and 2-wire SWD
• Two buttons and a RGB LED for user interaction
• Virtual COM port UART through USB on PC
• Onboard chip antenna with U.FL or SMA for conducted testing, selectable using 0-Ω resistors
• Onboard accelerometer and temperature sensor for out-of-box demo, with the option to isolate them from the
inter-integrated circuit (I2C) bus
• Micro USB connector for power and debug connections
• Headers for current measurement and external JTAG connection, with an option to use the onboard XDS110
to debug customer platforms
• Bus-powered device, with no external power required for Wi-Fi®
• Long-range transmission with a highly optimized antenna (200-meter typical in open air with a 6-dBi antenna
AP)
• Can be powered externally, working down to 2.3 V
2.2.1 Key Benefits
The CC3235MODx and CC3235MODAx modules offer the following benefits:
• CC3235MODS and CC3235MODAS are Wi-Fi modules that consist of the CC3235SM2ARGK while
the CC3235MODSF and the CC3220MODASF consist of the CC3235SF12ARGK single-chip MCUs,
respectively. The fully integrated and green/RoHS modules includes all required clocks, spi flash, and
passives
• 802.11 a/b/g/n: 2.4 GHz and 5 GHz
• FCC, IC/ISED, ETSI/CE, MIC. and SRRC 2Certified
• FIPS 140-2 Level 1 validated IC inside
• Multilayered security features, help developers protect identities, data, and software IP
• Low-power modes for battery powered application
• Coexistence with 2.4-GHz radios
• Industrial temperature: –40°C to +85°C
• CC3235MODx multiple-core architecture, system-on-chip (SoC)
• 1.27-mm pitch QFM package for easy assembly and low-cost PCB design
• Transferrable Wi-Fi Alliance® certification
• Application microcontroller subsystem:
– Arm® Cortex®-M4 core at 80 MHz
– User-dedicated memory
• CC3235MODS and CC3235MODAS variant includes 256KB RAM
• CC3235MODSF and CC3235MODASF variant is flash-based MCU with an integrated 1MB executable
flash and 256KB of RAM.
– Rich set of peripherals and timers
– 26 I/O pins with flexible multiplexing options
• UART, I2S, I2C, SPI, SD, ADC, and 8-bit parallel interface
• 8-bit synchronous image interface
• Timers and PWM
– Debug interfaces: JTAG, cJTAG, and SWD
•Wi-Fi network processor subsystem:
– Wi-Fi® core:
• 802.11 a/b/g/n 2.4 GHz and 5 GHz
• Modes:
– Access point (AP)
2Contact TI for more information on using SRRC ID Certification: www.ti.com/tool/SIMPLELINK-CC3XXX-CERTIFICATION
Hardware www.ti.com
14 CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
Copyright © 2021 Texas Instruments Incorporated

– Station (STA)
– Wi-Fi Direct® (only supported on 2.4 GHz)
• Security:
– WEP
– WPA™/ WPA2™ PSK
– WPA2 Enterprise
– Internet and application protocols:
• HTTPs server, mDNS, DNS-SD, DHCP
• IPv4 and IPv6 TCP/IP stack
• 16 BSD sockets (fully secured TLS v1.2 and SSL 3.0)
– Built-in power management subsystem:
• Configurable low-power profiles (always, intermittent, tag)
• Advanced low-power modes
• Integrated DC/DC regulators
•Multilayered security features:
– Separate execution environments
– Networking security
– Device identity and key
– Hardware accelerator cryptographic engines (AES, DES, SHA/MD5, CRC)
– Application-level security (encryption, authentication, access control)
– Initial secure programming
– Software tamper detection
– Secure boot
– Certificate signing request (CSR)
– Unique per device key pair
• Application Throughput
– UDP: 16 Mbps
– TCP: 13 Mbps
•Power-management subsystem:
– Integrated DC/DC converters support a wide range of supply voltage:
• Single wide-voltage supply, VBAT: 2.3 V to 3.6 V
– Advanced low-power modes:
• Shutdown: 1 µA, hibernate: 5.5 µA
• Low-power deep sleep (LPDS): 120 µA
• Idle connected (MCU in LPDS): 710 µA
• RX traffic (MCU active): 59 mA
• TX traffic (MCU active): 223 mA
– Wi-Fi TX power
• 2.4 GHz: 16 dBm at 1 DSSS
• 5 GHz: 15.1 dBm at 6 OFDM
– Wi-Fi RX sensitivity
• 2.4 GHz: –94.5 dBm at 1 DSSS
• 5 GHz: –89 dBm at 6 OFDM
• Additional integrated components
– 40.0-MHz crystal
– 32.768-kHz crystal (RTC)
– 32Mbit SPI serial flash
– RF filters, diplexer, and passive components
• Footprint compatible QFM package
– CC3235MODx: 1.27-mm pitch,
63-pin, 20.5-mm × 17.5-mm
• Module supports SimpleLink Developer's Ecosystem
www.ti.com Hardware
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
15
Copyright © 2021 Texas Instruments Incorporated

2.2.2 XDS110-Based Onboard Debug Probe
To keep development easy and cost effective, TI's LaunchPad development kits integrate an onboard debug
probe, which eliminates the need for expensive programmers. The CC3235MODSF LaunchPad has the
XDS-110-based debug probe (see Figure 2-4), which is a simple and low-cost debugger that supports nearly all
TI Arm device derivatives.
Figure 2-4. XDS-110 Debug Probe
The dotted line through J101 shown in Figure 2-4 divides the XDS110 debug probe from the target area. The
signals that cross this line can be disconnected by jumpers on J101, the isolation jumper block. More details on
the isolation jumper block are in Section 2.2.3.
The XDS110 debug probe also provides a "backchannel" UART-over-USB connection with the host, which can
be very useful during debugging and for easy communication with a PC. More details can be found in Section
2.2.4.
The XDS110 debug probe hardware can be found in the schematics in Section 7.2 and in the CC3235MOD
LaunchPad hardware design files.
Hardware www.ti.com
16 CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
Copyright © 2021 Texas Instruments Incorporated

2.2.3 Debug Probe Connection: Isolation Jumper Block
The isolation jumper block at jumper J101 allows the user to connect or disconnect signals that cross from the
XDS110 domain into the CC3235MOD target domain. This includes JTAG signals, application UART signals,
and 3.3-V and 5-V power.
Reasons to open these connections:
• To remove any and all influence from the XDS110 debug probe for high accuracy target power
measurements
• To control 3-V and 5-V power flow between the XDS110 and target domains
• To expose the target MCU pins for other use than onboard debugging and application UART communication
• To expose the programming and UART interface of the XDS110 so that it can be used for devices other than
the onboard MCU.
Table 2-1. Isolation Block Connections
Jumper Description
BRD Board Power. Supplies the board power from the onboard DC-DC converter. The board power includes the sensors,
LED, and the OPAMP used to drive the ADC input.
GND Ground reference
5V 5-V VBUS from USB
VBAT 3.3-V rail, derived from VBUS in the XDS110 domain. Can also be used to measure the current flowing into the
CC3235MOD.
RX Backchannel UART: The target CC3235MODSF receives data through this signal.
TX Backchannel UART: The target CC3235MODSF sends data through this signal.
RST This pin functions as the RST signal (active low).
TMS Serial wire data input (SWDIO) / JTAG test mode select (TMS)
TCK Serial wire clock input (SWCLK) / JTAG clock input (TCK)
TDO JTAG test data out
TDI JTAG test data in
VBUFFER Used to power the level shifters located on the emulator side of the board. The level shifters can be powered by
shorting this pin with a jumper. Removing the jumper enables low current measurement.
www.ti.com Hardware
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
17
Copyright © 2021 Texas Instruments Incorporated

2.2.4 Application (or "Backchannel") UART
The board supports a USB-based virtual COM port, using the SimpeLink™ MSP432E401Y Arm® MCU. The
LaunchPad is shipped with the UART lines from the CC3235MODSF connected to the UART on the MSP432E4
MCU. The CC3235MODSF's UART can also be routed to the 20-pin connector for use as a GPIO or external
UART. The selection is performed using jumpers on the board.
Figure 2-5 shows the UART routed to USB COM port. Ensure that a jumper is also placed on the VBUFFER
header to power the level shifters located on the emulator side of the board. Figure 2-6 shows the UART routed
to 20-pin header connector.
Figure 2-5. UART Routed to USB COM Port
Figure 2-6. UART Routed to 20-Pin Header Connector
Hardware www.ti.com
18 CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
Copyright © 2021 Texas Instruments Incorporated

2.2.5 JTAG Headers
The headers are provided on the board to isolate the CC3235MOD from the onboard XDS110-based JTAG
emulator. These jumpers are shorted by default when the board is shipped from TI. Figure 2-4 and Table 2-1
are for default configurations, and Figure 2-7 shows the external emulator connection. To connect an external
emulator, remove the isolation block JTAG jumpers and place the external emulator on the JTAG IN connector.
Figure 2-7. JTAG IN Connector (J6)
www.ti.com Hardware
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
19
Copyright © 2021 Texas Instruments Incorporated

2.2.6 Using the XDS110 Debug Probe with a Different Target
The XDS110 debug probe on the LaunchPad development kit can interface to most Arm® Cortex®-M devices,
not just the onboard target CC3235MODSF device. This functionality is enabled by the J2 10-pin Cortex-M JTAG
connector (see Figure 2-8) and a 10-pin cable, such as the FFSD-05-D-06.00-01-N (sold separately from the
LaunchPad development kit).
Figure 2-8. XDS110 OUT Connector (J2)
Header J2 follows the Arm Cortex-M standard; however, pin 1 is not a voltage sense pin. The XDS110 outputs
only 3.3-V JTAG signals. If another voltage level is needed, the user must provide level shifters to translate the
JTAG signal voltages.
1. Remove jumpers on the JTAG signals on the isolation block, including RST, TMS, TCK, TDO, and TDI.
2. Plug the 10-pin cable into J2, and connect to an external target.
J2 follows the Arm Cortex Debug Connector standard outlined in Cortex-M Debug Connectors.
3. Plug USB power into the LaunchPad development kit, or power it externally
JTAG levels are 3.3-V ONLY
Hardware www.ti.com
20 CC3235MODSF SimpleLink™ Wi-Fi® and IoT Solution With MCU
LaunchPad™ Hardware
SWRU548C – FEBRUARY 2019 – REVISED SEPTEMBER 2021
Submit Document Feedback
Copyright © 2021 Texas Instruments Incorporated