Freescale USB Development Board USB-KW40Z User’s Guide, Rev. 0, 10/2015
Freescale Semiconductor, Inc
15
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
