Freescale Semiconductor, Inc

FRDM-KL46Z

Page 12 of 17

5.1.3 Clock source

The Kinetis KL46 microcontrollers feature an on-chip oscillator compatible with three ranges of input crystal or

resonator frequencies: 32-40 kHz (low freq. mode), 3-8 MHz (high freq. mode, low range) and 8-32 MHz (high

freq. mode, high range). The KL46Z256on the FRDM-KL46Z is clocked from an 8 MHz crystal..

5.1.4 USB Interface

The Kinetis KL46 microcontrollers feature a dual-role USB controller with on-chip full-speed and low-speed

transceivers. The USB interface on the FRDM-KL46Z is configured as a full-speed USB device.

VREGIN must be powered to enable the internal circuitry of USB (by jumper J7)

5.1.5 Serial Port

The primary serial port interface signals are PTA1 UART0 RX and PTA2 UART0_TX. These signals are connected

the OpenSDA

5.1.6 Reset

The RESET signal on the K20 is connected externally to a pushbutton, SW2, and also to the OpenSDA circuit. The

reset button can be used to force an external reset event in the target MCU. The reset button can also be used

to force the OpenSDA circuit into bootloader mode. Please refer to section 5.2, Serial and Debug Adapter

(OpenSDA), for more details.

5.1.7 Debug

The sole debug interface on all Kinetis L Series devices is a Serial Wire Debug (SWD) port. The primary controller

of this interface on the FRDM-KL46Z is the onboard OpenSDA circuit (see section 5.2). However, an unpopulated

10-pin (0.05”) Cortex Debug connector, J11, provides access to the SWD signals. The Samtec FTSH-105-02-F-D or

compatible connectors can be added to the J11 through-hole debug connector to allow for an external debug

cable to be connected.

5.1.8 Segment LCD