NXP Semiconductors MPC5644A, Reference Manual, Page: 877 / 1735

Enhanced Time Processing Unit (eTPU2)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor 877
Single Match, Single Transition (sm_st)
In this mode the channel logic is functionally back-compatible to a TPU3 single action channel, but a
match or transition detection captures at once both timebases. The mode recognizes a single transition with
single match timeout. Either TDLA or MRLA generates service request and captures both timebases.
Assertion of TDLA blocks future assertions of MRLA.
Single Match, Double Transition (sm_dt)
In this mode, the first transition detection asserts TDLA, captures a timebase in CaptureA and enables
TDLB. The second signal transition asserts TDLB, blocks Match A, captures a timebase in CaptureB and
generates a service request.
Match A (before TDLB) captures into CaptureB the timebase selected by TBSA, in order not to overwrite
the captured value of TDLA.
This mode is used for scheduling one timeout condition on two input signal transitions (pulse timeout).
24.5.5.4.4 Channel Modes on Output Signal Generation
Since channel logic can generate output signal transitions based on Matches, the channel can be viewed as
working in the following primary mode groups for signal generation:
• Single Match: em_b_st, sm_st, sm_st_e, em_b_dt, sm_dt
• Double Match: em_nb_st, bm_st, m2_st, m2_o_st, em_nb_dt, bm_dt, m2_dt, m2_o_dt
The channel logic supports various match channel modes with single/double match, as explained in the
following subsections.
Either Match, Blocking Modes (em_b_st, em_b_dt)
On an output signal these modes are useful when using two different time bases to set a required signal
transition. The first match condition which is met sets a required pin action, captures both time bases,
blocks any effects of the other recognition, and generates a service request. Because the first match
recognition blocks the other, the microcode can get good separation in the function entry table as to which
match caused the timeout first, and both time bases are captured, enabling the microcode to compare one
timebase to the other at the moment of the match recognition. These modes can be used for:
• Scheduling a required pin action to the first match recognition of two different time bases.
• Cancelling a programmed pin action scheduled on one time base by match on another timebase (as
a consequence of
Table 24-56 ). Microcode has to set the OPAC register of the cancelling match to
no-action and the OPAC register of the other match to the required pin action which may be
blocked. If Match A is the cancelling match, it blocks the pin action also in case of two matches at
the same time, since it has priority in this case. If Match B is the cancelling match, it does not block
the pin action in case of two matches at the same time.
Either Match, Non Blocking Modes (em_nb_st, em_nb_dt)
On an output signal these modes are useful in combination with the ME bit set on the entry point, to define
an interlaced operation. For example, each match recognition can set a pin action, and the second pin