Preliminary Preliminary Preliminary Preliminary Preliminary
Preliminary Preliminary Preliminary Preliminary Preliminary
Preliminary Preliminary Preliminary Preliminary Preliminary
This manual describes the use and the features of the Glossy MSP430 debug probe for MSP430™ microcontrollers (MCUs). It includes information about the debugger probe hardware and software. It documents frequently asked questions on how to enable and disable certain features.
The Glossy MSP430 (see picture below) is a powerful debug probe for
application development supporting all MSP430 microcontrollers.
The Glossy MSP430 provides a USB interface to program and debug the
MSP430 MCUs in-system through the JTAG interface or the pin-saving
Spy-Bi-Wire (2-wire JTAG) protocol. Furthermore, the USB interface can
be used for Backchannel UART communication.
The Glossy MSP430 development tool supports development with all MSP430 MCUs and is designed for use with PCBs that contain MSP430 MCUs; for example, the MSP430 target socket boards.
The Glossy MSP430 debug probe includes the following features:
- Support for GDB 7 and newer;
- Automatically recognize old MSPGCC GDB version and switches protocol;
- Operating systems: OS X, Linux, Windows;
- Software configurable supply voltage between 1.8 V and 3.6 V at 100 mA;
- External voltage detection;
- Supports all MSP430 boards with JTAG header;
- Supports both JTAG and Spy-Bi-Wire (2-wire JTAG) debug protocols;
- Software breakpoints in flash, FRAM, and RAM
- Application backchannel UART included (VCP) in a dedicated connector;
- Application backchannel UART included (VCP) in the JTAG connector (mutually exclusive);
- Flash and FRAM programming support;
- Debug probe firmware field update is supported;
- Five JTAG clock speeds up to 9 MHz.
This is the primary hardware version for the Glossy MSP430 emulator. This is a build option for a rugged and professional looking device, which repurposes the plastic case of a generic STLink clone, which is quite cheap and easy to be found on eBay, Amazon or AliExpress.
The idea is to buy such a cheap clone and discard the chinese PCB and replace it with the solution provided by this KiCad Project.
This a picture of the referred device:
This project is completely based on the BluePill/BlackPill schematics and it will be the first release in accordance with the physical requirement:
For the assembly of this debugger you have to have a good electronic skill, since you will be handling with sensitive parts and very tiny solder pads.
The assembly instructions can be found on the FABRICATION.md file.
Before taking the STLink clone apart, lets use it to install the first firmware for the new board.
For that purpose, two options are available: the SWD4p or the SWD connector. The first is usually recommended since the later requires a 1.27" pitch SMD header, which is an optional feature for the firmware development.
So, the recommended access is through the 4-pin SWD4p pads. The pinout is marked on the silk-screen and the usual way is through the use of common jumper wires.
The table below shows the connection diagram for a Glossy MSP430 Board supplied by the STLink programmer:
| STLink 20-pin | SWD4p connector |
|---|---|
| Pin 7 | IO |
| Pin 9 | CK |
| Pin 10, 12 or 14 | GND |
| Pin 19 | 3v3 |
For this option, connect a USB cable only to the STLink programmer.
In some cases, the regulator of the STLink clone is unable to source enough current and the flasher program is unable to accomplish a connection. In those cases you should move the 3v3 wire from pin 19 to pin 1. Also, connect the USB cable to the Glossy MSP430 board power to provide voltage using the internal regulator:
| STLink 20-pin | SWD4p connector |
|---|---|
| Pin 1 | 3v3 |
| Pin 7 | IO |
| Pin 9 | CK |
| Pin 10, 12 or 14 | GND |
For this option, connect a USB cable only to the STLink programmer and another to the Glossy MSP430 USB connector.
Remove the big stick underneath. Eventually there will be glue residue stuck to the plastic case. Use alcohol to remove it.
Two screws closes the case. Just remove them with the proper screwdriver.
Before assembling all parts together, this is a good opportunity to remove the ST Logo from the plastic case.
The ST logotype can be erased using isopropyl alcohol, a rubber and paper towel.
Gently apply alcohol to the blue logo and patiently rubber it. Gradually
the blue tint dissolves. Before the alcohol dries out, swipe the area with paper towel or toilet paper, to clean the dissolved tint.
Repeat the process until no more ST image is left.
This is quite simple: Swap the PCB boards, removing the STLink clone PCB, then insert the Glossy MSP430 PCB. Close the plastic case and tighten the screws.
The following table is an overview of the capabilities and features for the Glossy MSP430 debug probe.
CAUTION
Never disconnect the JTAG or emulator USB cable during an active debug session. Make sure to perform a free-run before disconnecting the JTAG connector to avoid current consumption or functionality issues. And always terminate a running debug session properly, by clicking on the "Terminate" icon, before disconnecting the target device.
| Feature | Support |
|---|---|
| Supports all programmable MSP430 and CC430 devices | Y |
| Allows JTAG access protection (fuse blow) | N |
| Adjustable target supply voltage | Y |
| 4-wire JTAG | Y |
| 2-wire JTAG (SBW: Spy-Bi-Wire) | Y |
| BSL tool or mode | N |
| Backchannel UART (VCP) | Y |
| Support for Windows | Y |
| Support for MacOS | Y |
| Support for Linux | Y |
| EnergyTrace™ technology | N |
There are two different scenarios to configure the power supply when connecting a target board to the Glossy MSP430.
The Glossy MSP430 debug probe can supply targets with up to 100 mA through pin 2 of the 14-pin JTAG connector.
NOTE: Connection of a target board while power supply is active may cause a peak current that triggers the embedded polyfuse protection causing connection problems. Firmware tries to detect such scenarios and turns power supply output off for a while, to let fuse reset.
MSP430 target boards usually have a jumper to select the power supply mode. Removing this jumper, waiting a bit and reinsert it may help reset the fuse.
Example: If the target board has a capacitor on the VCC line with a capacity of more than 10 µF, it may cause an inrush current during capacitor charging that may exceed 60 mA. In this case, the current should be limited by the design of the target board, or an external power supply should be used.
Target VCC is selectable in a range between 1.8 V and 3.6 V in steps of 0.1 V.
Alternatively, the target can be supplied externally. In this case, the external voltage should be connected to pin 4 of the 14-pin JTAG connector. Glossy MSP430 adjusts the level of the JTAG signals to automatically match the external VCC.
NOTE: Only pin 2 (Glossy MSP430 tool supplies target) or pin 4 (target is externally supplied) must be connected. Both connections are not supported at the same time.
Even if an external supply powers the target device on the target socket module and any user circuitry connected to the target socket module, the Glossy MSP430 tool continues to be powered from the PC through the USB interface.
Note that a weak 3.3V voltage reference is also internally connected to the pin 4, so if no voltage level is provided by the target board, 3.3V will be used.
This section describes how to install the drivers for Glossy MSP430 debug probe. The drivers are needed to enable the IDE (integrated development environment) to use the debug probe that is connected to the system.
Except for Windows 7, Glossy MSP430 drivers are automatically installed by the Operating System. It just requires standard CDC drivers.
This section includes all specifications and features for the Glossy MSP430 debug probe. The debug probe hardware and different debug mode configuration and setting are described.
The Figure below is an overview of the MSP development ecosystem showing the relations between IDE, GCC Toolchain, debug probe and the MSP device itself.
For embedded development using the Glossy MSP430 debug probe it requires an IDE that is able to interoperate with the GCC Toolchain. There are many options nowadays, like VSCode, Eclipse, Code::Blocks and the Visual Studio + VisualGDB plugin.
The GCC Toolchain is a complete open source C/C++ compiler, which is able to produce high quality binary code. With the exception of the GCC 8.3.1 release they are very stable and optimized.
The GCC 8.3.1 version does not produce a good bit shift operation for the legacy MSP430 CPU core, so I generally cannot recommend. But for a CPUv2 (20 bit address support) this is probably not an issue.
Another tool installed with the toolchain is the GDB debugger. This debugger is able to connect to a target using the GDB Remote Serial Protocol, either through a network link or a serial communication port.
TI offers a very good port of the Mitto Systems GCC toolchain, besides one can also use the now very outdated MSPGCC.
Another good source of prebuilt MSP430 compilers can be found on the SysProgs website.
On the other hand, the Glossy MSP430 debugger connects to a MSP430 MCU through a JTAG interface. It also implements a virtual serial port using its USB connection. This communication port understands the GDB Remote Serial Protocol and translates GDB requests into JTAG instructions, controlling the MCU.
The Glossy MSP430 debugger supports the use of software breakpoints in Flash, FRAM, and RAM. Software breakpoints let the user set up to 32 breakpoints during an active debug session.
Without software breakpoints enabled, the number of breakpoints that can be set is limited to the number of hardware breakpoints available by the specific MSP MCU. The Glossy MSP430 debugger prefer the use of hardware breakpoints as much as possible. However, if the MSP breakpoint logic runs out of hardware breakpoints, software breakpoints are used automatically.
A software breakpoint is a smart feature, that programs into the desired code position an invalid CPU instruction (i.e. a 16-bit value that cannot exists in a normal program) and through one of the hardware breakpoints, monitors the Instruction Fetch operation to stop the CPU when this particular 16-bit value is fetched.
The firmware contains a memory manager that replaces memory positions where breakpoint exists to accommodate the proper 16-bit value, when running, reading or fetching these positions, so that the original programmed behavior is always followed.
NOTE: When the debug session is closed, all software breakpoints are erased and the original memory content is restored.
The Glossy MSP430 does not have the hardware provision to blow JTAG fuses. So it is not recommended as a production tool, since you cannot lock the access to the MCU and provide IP protection.
The Glossy MSP430 allows you to configure the protocol speed in five different rates, according to the following table:
| Interface | Level 1 | Level 2 | Level 3 | Level 4 | Level 5 |
|---|---|---|---|---|---|
| SBW (*) | 141 KHz | 281 kHz | 563 KHz | 1.13 MHz | 2.25 MHz |
| JTAG | 563 KHz | 1.13 MHz | 2.25 MHz | 4.5 MHz | 9 MHz |
(*) Under development: Values are prognostics.
When connecting the Glossy MSP430 into a PC two communication ports are added to the OS device list. Enumeration of these devices depends on the host OS, but usually the first device refers to the GDB port, that implements a GDB Remote Serial Protocol.
A second communication port is added that implements common low voltage serial port, accessible for your target board in a properly designed JTAG connector.
A second parallel connection also exists on the 4-pin connector at the top of the case, which is a very handy option for a diversity of scenarios.
Note that both connections share the same pins, so they are mutually exclusive.
It is also important to note that regardless of the connector you use, the voltage realm of the target will be used. This means that pin 2 of the JTAG connector and pin 4 of the UART connector are connected at the same power supply.
The Glossy MSP430 shows its operating state using a single dual color LED. The next table shows all possible states:
| Color | State | Function |
|---|---|---|
| Off | --- | Power off or not functional. |
| Green | On | Awaiting GDB connection. |
| Green | Blinking | Ongoing communication on one of the VCP port. |
| Red | On | Active JTAG/SBW debug session. |
| Red | Blinking | Active Debug session and ongoing communication. |
Do not disconnect the target board while a debug session is active.
The image below shows the pinout of the Glossy MSP430 JTAG and the UART connectors:
The following table describes the electrical state of every JTAG pin after debug probe power up.
| Pin | Name | After Power Up | JTAG Active | SBW Active |
|---|---|---|---|---|
| 1 | TDO/TDI | Hi-Z, PU | In, TDO | In and Out, SBWTDIO |
| 2 | VCC_TOOL | 3.3V | Target Vcc | Target Vcc |
| 3 | TDI | Hi-Z, PU | Out, TDI | Hi-Z, PU |
| 4 | VCC_TARGET | In, Vcc sense | In, Vcc sense | In, Vcc sense |
| 5 | TMS | Hi-Z, PU | Out, TMS | Hi-Z, PU |
| 6 | n/c | not connected | not connected | not connected |
| 7 | TCK | Out, Vcc | Out, TCK | Out, SBWTCK |
| 8 | TEST | Out, GND | Out, Vcc | Out, Vcc |
| 9 | GND | Ground | Ground | Ground |
| 10 | n/c | not connected | not connected | not connected |
| 11 | RST | Out, Vcc | Out, RST | Out, GND |
| 12 | TXD | Hi-Z, PU | n/a | n/a |
| 13 | GND | Ground | Ground | Ground |
| 14 | RXD | Hi-Z, PU | n/a | n/a |
Term and Abbreviations (in alphabetical order):
- Hi-Z: High impedance
- n/a: Does not apply to JTAG or SBW state
- PD: Weak Pull Down to Ground
- PU: Weak Pull Up to Target VCC
- RST: Test Reset
- RXD: UART receive data
- TCK: Test Clock
- TDI: Test Data In
- TDO: Test Data Out
- TEST: Test bus activate
- TMS: Test Mode Select
- TXD: UART transmit data
- VCC_TARGET: Firmware adjustable voltage that sources the target
board. Do not connect to
VCC_TOOL; these are mutually exclusive functions - VCC_TOOL: Input used to read samples of the target reference voltage. Do not connect to
VCC_TARGET; these are mutually exclusive functions
Note that state for the TXD and RXD pins on the table does not depends JTAG or SBW use.
These lines are activated only when the backchannel UART is opened on the host (i.e. a PC software opens the COM port).
| Attribute | Value | Comments |
|---|---|---|
| Mechanical | ||
| Size (without cables) | 80 x 48 x 28 | Units in mm |
| JTAG cable length | 20 cm (max) | |
| Interface | ||
| USB Interface | USB 2.0, full speed | max. 500 mA |
| Target Interface | JTAG 14-pin | See pinout above |
| Dedicated 4-pin UART | ||
| JTAG Interface | Electrical | |
| Target Output Voltage | 1.8 to 3.6 Volts | Output on Pin 2 |
| Target Output Current | 100 mA | Protected by Polyfuse |
| External Target Supply | 1.8 to 3.6 Volts | Input on Pin 4 |
| JTAG Fuse Blow | Unsupported | |
| Timing | ||
| JTAG Clock Speed | up to 9 MHz | Selectable by Software |
| SBW Clock Speed | up to 9 MHz | RC on target RESET pin limits the clock speed |
| Data Rate | ||
| Flash write speed (JTAG) | Up to NN kB/s | |
| Flash write speed (SBW) | Up to NN kB/s | |
| FRAM write speed (JTAG) | Up to NN kB/s | |
| FRAM write speed (SBW) | Up to NN kB/s | |
| UART Interface | Electrical | |
| Target Output Voltage | 1.8 to 3.6 Volts | Shares same JTAG target supply voltage |
| Target Output Current | 100 mA | Combined with JTAG requirements |
| Timing | ||
| Baud rate | From 4800 bps | Software selectable |
| up to 115200 bps |