Chapter 24 Cross Triggering Unit (CTU)
MPC5602P Microcontroller Reference Manual, Rev. 4
Freescale Semiconductor
615
When a trigger is linked to the ADC, an associated ADC command (or stream of commands) is generated.
The ADC Commands List Control Register (CLCR
x
) sets the assignment to an ADC command or to a
stream of commands. When a trigger is linked to a timer or to the external trigger, a pulse with an active
rising edge is generated. Additional features for the external triggers are available:
The external trigger output has:
•
Pulse mode
•
Toggle mode
In Toggle Mode, each trigger event is linked to the external trigger, the external trigger pin toggles. The
ON-Time for both modes (Pulse mode and Toggle mode) of the triggers is defined from a COTR register
(Control On Time Register). A guard time is also defined from the same register at the same value of the
ON-Time. A new trigger will be generated only if the ON time + Guard Time has past. The ON-Time and
the Guard Time are only used for external Triggers.
External signals can be asynchronous with motor control clock. For this reason a programmable digital
filter is available. The external signal is considered at 1 if it is latched N time at 1, and is considered at 0
if it is latched N time at 0, where N is a value in the digital filter control register.
Trigger events in the SU can be initiated by hardware or by software, and an additional software control
is possible for each trigger event (as for the MRS), so 1 bit for each trigger event in the CTU Control
Register is used to generate an equivalent software trigger event. Each of these bits is cleared by a
respective hardware or software trigger event.
Figure 24-7. Scheduler subunit
CTU Clock
TRIGGER_0
ETIMER0_TRG
Prescaler
ADC Commands List Registers
(double-buffered)
ADC Commands List Control
Registers (double-buffered)
ADC Command
Generator
Trigger
Handler
(1, 2, 3, 4)
Subunit Clock
Subunit Clock
Trigger 0..7
MRS
eT1 Trigger
Generator
eT2 Trigger
Generator
Ext. Trigger
Generator
FIFOs
Subunit
Clock
Trigger
0..7
ETIMER1_TRG
EXT_TRG
FIFO_0
FIFO_1
TRIGGER_1
ADC_CMD_1
ADC_CMD_0
NEXT_CMD_1
NEXT_CMD_0
Ready
Ready
Trigger Handler Control Register
(double-buffered)
Ready
Ready