FRDMKE06UG, Freedom KE06 User’s Guide, Rev. 0, 03/2014
Freescale Semiconductor, Inc.
5
Serial and Debug Adapter (OpenSDA)
Figure 3. OpenSDA block diagram
OpenSDA is managed by a Kinetis K20 MCU built on the ARM
®
Cortex
™
-M4 core. The OpenSDA
circuit includes a status LED (D4) and a reset pushbutton (SW1). The pushbutton asserts the reset signal
to the KE06 target MCU. It can also be used to place the OpenSDA circuit into Bootloader mode by
holding down the reset pushbutton while plugging the USB cable to USB connector J6. Once the
OpenSDA enters bootloader mode, other OpenSDA applications such as debug app can be programmed.
SPI and GPIO signals provide an interface to the SWD debug port of the KE06. Additionally, signal
connections are available to implement a UART serial channel. The OpenSDA circuit receives power
when the USB connector J6 is plugged into a USB host.
3.1
Debugging interface
Signals with SPI and GPIO capability are used to connect directly to the SWD of the KE06. These signals
are also brought out to a standard 10-pin (0.05”) Cortex Debug connector (J7) as shown in Figure 4. It is
possible to isolate the KE06 MCU from the OpenSDA circuit and use J7 to connect to an off-board MCU.
To accomplish this, cut the 0 ohm resistor R58. This will disconnect the SWD_CLK pin to the KE06 so
that it will not interfere with the communications to an off-board MCU connected to J7.
When KE06 on FRDM board is 5V powered, and the OpenSDA is power off, there need to connect an
external debugger to debug KE06 on board.
