This Freescale tower board is based on the K21DN512VMC5 which is a 50MHz device from the performance and integration K21 family with Cortex-M4 core and USB. This K21 device has 512k Flash and 64k SRAM and is in an 121 pin MAPBGA thin-profile package, whereby the 50MHz K21 is also available in 80 pin LQFP and its memory ranges of 192k...512k Flash with 32k...64k SRAM. K21 parts with 120MHz maximum CPU frequency and FPU are furthermore available in 121 pin MAPBGA or 144 pin MAPBGA/LQFP and memory ranges of 640k..1M Flash and 128k RAM. There is an 8MHz crystal on the board for clocking the part.

Full details and documentation for this board can be obtained from the Freescale web site: TWR-K21D50M

To configure the µTasker project for this board simply enable the define TWR_K21D50M in the project's config.h file. The compiler needs to be set to build for Cortex M4 (and not Cortex M0+) and the linker script K_512_64.ld should be selected [K_512_64_BM.ld for downloadable version] {the linker script extension may vary for different compilers, whereby *.ld is valid for GCC}

TWR-K21D50M Binaries

Here are some binary files that can be loaded to the board. These were built using the µTasker applications (serial loader and V1.4 application) and can be simply generated using the supported compilers/IDEs [these were built using GCC], built using different configuration options or modified to suit specific requirements or hardware derived from this board :

  • uTaskerSerialBoot_TWR-K21D50M_KBOOT_HID_UART_MSD.bin KBOOT compatible USB-HID loader with composite USB-MSD loading, as well as KBOOT UART loading on UART 2 at 57'600 Baud allowing applications to be loaded at link address 0x8080 (using Freescale's KBOOT USB connection, or KBOOT UART at 57'600 Baud or USB-MSD when the board appears as upload hard disk) [16.4k]. When operating, the green LED blinks at 5Hz. To force the loader reset the board with push button SW3 held down. To disable the watchdog reset the board with push button SW2 held down. This can be loaded using CodeWarrior's Flash utility via the TWR-K21D50M's OSJTAG debug interface. Note that the loader limits application sizes to 70k - it can be built without limits using the µTasker project.
  • uTaskerV1.4.8_BM_TWR-K21D50M_8080.bin TWR-K21D50M application with command-line menu on the virtual COM connection (115'200 Baud) with various menu items (as well as on UART2), including the ability to switch to USB-UART-2 bridge mode with end-to-end flow control. Output from the on-board accelerometer can be viewed in the I2C menu. Low power modes can be set in the application menu (when LLS has been entered, pressing the push button SW3 will wake and return to the fully functional mode - more details of this operation can be found in Low-Leakage Wakeup (LLWU) Support). The USB device is a composite USB-CDC with four interfaces, whereby the first is connected to the command line shell (in the USB menu it is possible to command a bridging mode to UART2).
    The second interface performs full-time USB-UART bridging to UART0 (Tx = PTA14, Rx = PTA15).
    The third interface performs full-time USB-UART bridging to UART1 (Tx = PTC4, Rx = PTC3).
    The fourth interface performs full-time USB-UART bridging to UART3 (Tx = PTC17, Rx = PTC16).
    Drivers that can be used for this device are available below. The processor runs at 48MHz for USB compatibility. [39.3k].
    Linked to 0x8080, this binary image can be loaded with drag-and-drop onto the upload disk that appears when the serial loader is operating or using the KBOOT loader's USB or UART connections. When the application is running the green LED blinks at 2.5Hz.
  • uTaskerV1.4.8_TWR-K21D50M.bin The same TWR-K21D50M application as stand-alone software that can be loaded using CodeWarrior's Flash utility via the TWR-K21D50M's OSJTAG debug interface [40.3k].

  • uTaskerFreescaleMultiVirtualCOM.inf USB CDC installation file for 32-bit windows (usable for 1..6 USB-CDC composite interfaces).
  • uTaskerFreescaleMultiVirtualCOM_64bit.inf USB CDC installation file for 64-bit windows (usable for 1..6 USB-CDC composite interfaces). See the following for a guide to installing unsigned drivers on Windows 8.1

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µTasker Kinetis TWR-K21D50M support. Copyright (c) 2004..2018 M.J.Butcher Consulting