PXS20RM Datasheet, PDF (251/1368 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

Cross-Triggering Unit (CTU)
The prescaler for TGS and SU can be 1,2,3,4 (PRES bits in the TGS Control Register).
An example timing for the TGS in Triggered Mode is shown in Figure 13-4. The red arrows indicate the
MRS occurrences, while the black arrows indicate the trigger event occurrences, with the relevant delay
in respect to the last MRS occurrence.
Delay T₀
Delay T₁
Delay T₂
Delay T₂
Figure 13-4. Example timing for TGS in triggered mode
13.4.5 TGS in sequential mode
The structure of the TGS in sequential mode is shown in Figure 13-5.
The 32 input events (16 signals with 2 edges for signal), which can be individually enabled, are OR-ed in
order to generate the event signal (ES). The ES is used to enable the reload of the TGS counter register and
to pilot the 3-bits counter, in order to select the next active trigger. One of the 32 input events can be
selected, through the MRS_SM (master reload selection sequential mode) 5-bits in the TGS control
register, to be the MRS, that enables the reload of the triggers list and resets the 3-bits counter (incoming
events counter), i.e. the MRS is the signal linked with the control cycle defined as the time window
between two consecutive MRSs. In this mode, each incoming event sequentially enables only one trigger
event through the 3-bits counter and the MUX. The MUX is a selection switch which enables, according
to the number of event signals occurred, only one of the eight trigger signals to the scheduler subunit.
Sequences of up to eight trigger events can be supported within this control cycle.
For the other features see the previous paragraphs.
Freescale Semiconductor
PXS20 Microcontroller Reference Manual, Rev. 1
13-5