Internal signals

Internal signals represent interconnections between processor internal peripherals, a peripheral produces signal which is used by different peripherals. Examples of internal signals are:

Trigger - signal asserting request (example of trigger source is Program Delay Block or any timer).
Internal voltage sources - internal reference or programmable voltage sources (produced by D/A converter).

In Processor Expert, each internal signal is represented by name, is composed of name of peripheral producing the signal and function of the signal. Some examples are CMP0_output, TMR0_overflow, and DAC6b_output. However, it is not guaranteed that the same internal signal will have exactly the same representation across all components. In embedded components, internal signals represented by their name, are typically present on the consumer peripheral side as inputs to the embedded components. On the signal producer side, internal signal generation control is peripheral specific.

Some examples of internal signals available on KL25 Kinetis MCU: Analog comparator input (CMP) peripheral can compare two types of analog signal sources: external, connected through package pin, or internal, connected using internal signal. Figure below shows list of sources available for the CMP0 in the AnalogComp_LDD component.

Figure 1. Analog comparator input selection in AnalogComp_LDD

From the list, internal signals are Bandgap (constant voltage reference), DAC12b0_Output (output of the 12-bit DA converter 0), and DAC6b0_Output (output of the 6-bit DA converter 0).

Analog-to-digital converter (ADC) trigger - A/D conversion can be triggered from the package pin or from number of internal peripherals. Figure below shows some of the triggers offered in the ADC_LDD component Trigger input property.

Figure 2. A/D converter trigger selection in ADC_LDD

From the list, internal signals are CMP0_output (Comparator 0 output), Low_power_timer (Low power timer event), PIT_trigger_0/1 (Periodic interrupt timer 0 and 1 event), RTC_alarm (Real-time clock alarm event), RTC_seconds (Real-time clock second event), TPM0_Overflow (Timer PWM module 0 overflow event), TPM1_Ch0_Flag (Timer PWM module 0 channel 0 event) and TPM1_Overflow (Timer PWM module 1 overflow event).

Timer synchronization - some timers can be synchronized by trigger. Figure below shows how selection of appropriate trigger looks like in the Init_TPM component. This example also shows that selection of internal signals in Peripheral Initialization components is same as in high-level and LDD components.

Figure 3. Timer synchronization trigger selection in Init_TPM

From the list, internal signals are CMP0_output (Comparator 0 output), Low_power_timer (Low power timer event), PIT_trigger_0/1 (Periodic interrupt timer 0 and 1 event), RTC_alarm (Real-time clock alarm event), RTC_seconds (Real-time clock second event), TPM0/1/2_Overflow (Timer PWM module 0, 1 and 2 overflow event).