CPU_42A-V1
CPU Board XMC4200 Actuator
Hardware Description
Board User's Manual
14
Revision 1.0, 2013-02-19
2.5
Clock Generation
An external 12 MHz crystal provides the clock signal to the XMC4200 microcontroller. The drive strength of the
oscillator is set to maximum by software, in order to ensure a safe start-up of the oscillator even under worst
case conditions. A serial 510 Ohm resistor will attenuate the oscillations during operations.
For the RTC clock a separate external 32.768 kHz crystal is used on board.
Figure 9
Clock Generation
2.6
Boot Option
During power-on-reset the XMC4200 latches the dip switch SW300 settings via the TCK and the TMS pin.
Based on the values latched different boot options are possible.
Table 4
Boot Options Settings
BSL (TMS)
CAN/UART (TCK)
Boot Option
OFF (1)
UART (0)
Normal Mode (Boot from flash)
ON (0)
UART (0)
ASC BSL Enabled (Boot from UART)
OFF (1)
CAN (1)
BMI Customized Boot Enabled
ON (0)
CAN (1)
CAN BSL Enabled (Boot from CAN)
Figure 10 Boot Options Switch
Boot_Switch.emf
Boot
Option
Switch
