Freescale USB Development Board USB-KW40Z User’s Guide, Rev. 0, 10/2015

Freescale Semiconductor, Inc

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USB-KW40Z development board

4.2.4.2.1

OpenSDA interface clock

The USB-KW40Z provides one clock source for the OpenSDA MK22FN512 MCU.

•

8 MHz Reference Oscillator - Figure 12 shows the external 8 MHz external crystal X1. This

mounted crystal must meet MK22FN512 specifications. It also provides C44 and C45 to the bulk

of the crystal load capacitance.

Figure 12. USB-KW40Z MK22FN512 8 MHz clock source

4.2.4.2.2

MK22FN512 peripheral

functions

The USB-KW40Z OpenSDA interface circuit also includes one switch button, to assist in MK22FN512

MCU hardware reset. Figure 13 shows the push button for MK22FN512

Figure 13. USB-KW40Z MK22FN512 push button & LED