Virtual Serial Port; Kl25Z Microcontroller - Freescale Semiconductor FRDM-KL25Z User Manual

accomplish this, cut the trace on the bottom side of the PCB that connects J11 pin 1 to J11 pin 2. This
will disconnect the SWD_CLK pin to the KL25Z so that it will not interfere with the communications to
an off-board MCU connected to J6.
Note that J6 is not-populated by default. A Samtec FTSH-105-02-F-D or compatible connector can be
added to the J6 through-hole connector. A mating cable, such as a Samtec FFSD IDC cable, can then be
used to connect from the OpenSDA of the FRDM-KL25Z to an off-board SWD connector.

5.2.2 Virtual Serial Port

A serial port connection is available between the OpenSDA MCU and pins PTA1 and PTA2 of the KL25Z.
Several of the default OpenSDA Applications provided by Freescale, including the MSD Flash
Programmer and the P&E Debug Application, provide a USB Communications Device Class (CDC)
interface that bridges serial communications between the USB host and this serial interface on the
KL25Z.

5.3 KL25Z Microcontroller

The target microcontroller of the FRDM-KL25Z is the KL25Z128VLK4, a Kinetis L series device in an 80
LQFP package. The KL25Z MCU features include:
 32-bit ARM Cortex-M0+ core
- up to 48 MHz operation
- Single-cycle fast I/O access port
 Memories
- 128 KB flash
- 16 KB SRAM
 System integration
- Power management and mode controllers
- Low-leakage wakeup unit
- Bit manipulation engine for read-modify-write peripheral operations
- Direct memory access (DMA) controller
- Computer operating properly (COP) Watchdog timer
 Clocks
- Clock generation module with FLL and PLL for system and CPU clock generation
FRDMKL25ZUM
Figure 5. SWD Debug Connector
FRDM-KL25Z User's Manual Page 8 of 14