Clock Generation; Boot Option; Figure 9 Clock Generation; Figure 10 Boot Options Switch - Infineon CPU-42A-V1 Manual

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)
OFF (1) UART (0)
ON (0) UART (0)
OFF (1) CAN (1)
ON (0) CAN (1)
Boot
Option
Switch
Figure 10 Boot Options Switch
Board User's Manual
Normal Mode (Boot from flash)
ASC BSL Enabled (Boot from UART)
BMI Customized Boot Enabled
CAN BSL Enabled (Boot from CAN)
14
CPU Board XMC4200 Actuator
Hardware Description
Boot Option
Boot_Switch.emf
Revision 1.0, 2013-02-19
CPU_42A-V1