MPC563XM Reference Manual, Rev. 1
730
Freescale Semiconductor
Preliminary—Subject to Change Without Notice
23.2.2
Detailed Signal Descriptions
23.2.2.1
ipp_do_etpuch_[1|2]([0-31]) — eTPU Channel Output Signals
Each channel output signal is associated with a channel. The microcode may affect the logic level of an
output signal
1
by implementing one of two actions:
•
Specify the logic level output to the signal when there is a match or a transition.
•
Immediately force a logic level.
The output signal may also be forced to a logic level, independently of the output value from the channel
logic, by one of the four (each Engine) output disable input signals ipp_ind_etpuodis (see
“ipp_ind_etpu_odis_[1|2]([0-3]) eTPU Channel Output Disable Signals
”).
The output signal driver may be, depending on MCU integration, enabled by the output buffer enable
internal signal that comes from eTPU. In this case, the output buffer can be controlled by microcode,
through a specific microinstruction field. There is one independent output buffer Enable signal for each
channel. For more information on output control from microcode, refer to
Section 23.4.9.3.3, “Transition
Detection and Pin Action Control
23.2.2.2
ipp_ind_etpuch_[1|2]([0-31]) — eTPU Channel Input Signals
Each channel input input signal is associated with a channel. The microcode can directly control the effect
of the transition edge. Each channel can be programmed to sense a transition when a rising and/or falling
edge is detected. The channel logic can also process two transition events, and relate these events to each
other and to other programmed timer events. The edge sensitivities of the two transition events are
configured independently by microcode. For further information refer to
Section 23.4.9.3.3, “Transition Detection and Pin Action Control
Each channel input signal has an associated synchronizer made of two flip-flops sampling the signal on
every other system clock
2
, followed by a digital filter. This digital filter can work in three sub-modes,
whose purpose is to filter out noise pulses that have width less then a programmed value of system clocks,
preventing these transitions from being input to the transition detect logic. The synchronizer and digital
filter are guaranteed to pass pulses that are greater than a programmed value. All channel input filters in
one Engine work on the same mode and sampling clock. For more information on channel input filters,
refer to
Section 23.4.5.6, “Enhanced Digital Filter - EDF
”. In one of the Angle Modes, the output of the
digital filter of channel 0 is replaced by the output of TCRCLK signal digital filter (see
23.2.2.3
ipp_ind_tcrclk_etpu_[1|2] — Time Base Clock Signal — TCRCLK
TCRCLK is an input signal used to control the Time Bases TCR1 and TCR2. There is one independent
TCRCLK input for each Engine. For pulse accumulator operations TCRCLK can be used as a gate for a
counter based on the system clock divided by eight. For Angle operations TCRCLK can be used to get the
1.
Note that the minimum pulse width is one microcycle (two system clocks), and slow 5V pads may not be able to transfer it
on time. For generation of very short pulses the eTPU pads have to be programmed by the system integration for fast
operation mode with the voltage levels defined for fast pad operation in the MCU technology.
2.
Sampled on the T4 microcycle phase, see
Section 23.6.1, “Microcycle and I/O Timing
.