Explore the Features of MCU-Link Pro
MCU-Link Pro is the latest ARM Cortex-M series core debugger tool from NXP. Some of its features are inherited from the past LPC-LINK2. But overall it was redesigned and introduced and many new features. These additional functions make the MCU-Link Pro a very powerful debugging tool. This article will explore these features and highlight interesting and useful ones. These functions mainly include the following aspects.
MCU-Link Pro support SWD only. It doesn’t support JTAG. The main controller in the board is LPC55S69. There is level shifter circuit between the port and LPC55S69. It makes the board can debug the target board work at 1.2V to 5V. It has reference voltage trace circuit which is use to trace the target board voltage. It can trace the port automatically, needn’t any settings. The MCU-Link Pro also can supply 1.8V/3.3V to target board. The maximum current is 350mA. This is done by connecting J6 and selecting by J5.
The maximum speed of SWO is 9.6Mbit/s.
Same as <PC-Link, MCU-Link Pro support CMSIS-DAP and Jlink firmware. These firmware are kept updating. The latest firmware of CMSIS-DAP is 2.25. If the firmware version is old, there will be a message jump out telling customer to update it when connecting to computer. We can see that the new version gives two VCOM while the original version only have one. The new VCOM use J26-4 and J26-5.
MCU-Link pro provides a very interesting real-time function of current and voltage measurement. It can capture a burst of samples of target current usage, the target supply voltage, the shield current, the analog input, the debug interface reference voltage, or target power consumption at up to 100ksps. This information is displayed in a graph and can also be exported for further analysis. The average value of the collected data can also be displayed. And based on the current and voltage data, the power consumption can also be calculated and displayed in the graph. The place where the red line is drawn in the figure below is the real-time voltage at the time point of the mouse.
What's more interesting is that the energy measurement function does not need to activate the debug to capture the data, it is offline and has a separate data channel. But it can also be linked to a session if such a debug session exists. This is very useful in debugging various low-power applications. Not only can you see the power consumption change under each step of the command, but you can also check the power change rule for a long period of time when the system is running. Since there is a separate data channel, you can even debug the program in KEIL and watch the current change in MCUXpresso.
The MCU Link Pro has two current measurement configurations, each with a maximum measurable current. This is to achieve maximum measurement accuracy for a variety of different objectives. There are two automatically controlled ranges in each configuration to provide greater precision. The automatic switching from low current measurement to high current measurement is completely controlled by hardware.
Each time the MCU Link Pro is powered up, the measurement circuit calibrates itself. There is no need to disconnect/reconnect the MCU Link Pro before calibration due to transistors are used to isolate the sensing circuit from the target power supply to avoid contention and to ensure a known voltage is applied to the system during calibration.
At high sample rates, the MCUXpresso IDE may not capture all data, so the sample rate may need to be adjusted using the configuration options in the energy measurement configuration settings in the tool.
If the target current exceeds the maximum current in the selected range, the measurement will saturate and cut off and will therefore be inaccurate.
Blhost and MCU-Link Pro
The most noteworthy feature of MCU Link Pro is its USB to SPI and I2C bridge functions. This enables the computer to send I2C and SPI signals directly through USB.
This powerful function is not ignored by blhost. The new version of blhost can support this function and adds a new command parameter '- L'. Specifically, '- L SPI' refers to the SPI interface and '- L I2C' refers to the I2C interface. The following figure shows the test results on frdm-k64f. It can be clearly seen in the figure that the SPI interface of MCU Link Pro can communicate with mcuboot firmware on k64 and download the encryption program to flash.
In addition to KINETIS, this function is most suitable for i.mxrt600 and I mxRT500。 These two chips have serial ISP mode. User can download the program to ram through SPI or I2C port, and then directly let it run. Many users have this usage. In the previous examples in SDK, a board of twr-kv46 or twr-k65 or frdm-kl25 was required to receive command and data from UART and translate them to SPI and I2C command. Since there is no direct interface on these boards, flying wires are required, which is very troublesome. Moreover, NXP only provides firmware for these three boards. If you want to use other chips or boards, you must also transplant firmware. It's also very troublesome. But with MCU Link Pro, it's all very easy and pleasant.
In order to better expand the use of bridge functions, NXP has provided libusbsio library. By calling this library, you can realize the USB to SPI \ I2C \ GPIO function in your own application. I also made the upper computer tools for writing kinetis ezport and flash according to the libusbsio library provided by NXP. I introduced this point in detail in my last article. Interested friends can read my article.
It is not enough to provide libraries based on windows and Linux. NXP also provides a python library. This library is based on python3 and can be installed through the following command
>pip install libusbsio
Its usage is not described in detail in the libusbsio documentation. Here is a general introduction. The following is an initialization procedure of libusbsio.
import logging import logging.config from libusbsio import * # enable basic console logging logging.basicConfig() # load DLL from default directory sio = LIBUSBSIO(loglevel=logging.DEBUG) # the main code # calling GetNumPorts is mandatory as it also scans for all connected USBSIO devices numports = sio.GetNumPorts() print("SIO ports = %d" % numports) if numports > 0 and sio.Open(0): print("LIB version = '%s'" % sio.GetVersion()) print("SPI ports = %d" % sio.GetNumSPIPorts()) print("Max data size = %d" % sio.GetMaxDataSize()) if(sio.GetNumSPIPorts() > 0): spi = sio.SPI_Open(1000000, portNum=0, dataSize=8, preDelay=100) if spi: data, ret = spi.Transfer(spi_ssel, spi_ssel, b"Hello World") sio.Close() else: print("No USBSIO device found")
Line 9 is to open an instance of libusbsio library;
Line 14: get the number of usbsio ports of all USB bridges;
Lines 18, 19 and 20 are the read version information, the number of SPI ports and the maximum size of SPI cache;
Line 22: open an SPI interface;
Line 24, start transmitting data.
It can be seen from the above that the use process is relatively simple. And these commands are very similar to those of the C language library.
A secondary controller LPC804 on the board
There is also an lpc804 on the MCU Link Pro board. This chip is confusing here. What is it for? Its UART, SPI and I2C ports are all connected for external use. But what's the use? One conceivable application is that the UART port is connected to the newly added vcom2, and then the SPI or I2C works in the slave mode. As a listener, it monitors the SPI or I2C bus to be debugged and displays it on the computer terminal.
The LPC804 debug interface is the same as the debugging port of MCU Link Pro. Maybe the board itself is a development board, so that users can develop lpc804 programs? In addition, its UART-ISP port is connected to a UART port of LPC55S69. It seems that in the future, it can communicate with each other through the new version of CMSIS-DAP firmware. Let's look forward to new ways of playing in the future.