NXP Semiconductors MPC5644A, Reference Manual, Page: 947 / 1735

Enhanced Time Processing Unit (eTPU2)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor 947
24.5.9.3.3 Transition detection and pin action control
IPACA/B and OPACA/B fields are used to configure transition detection sensitivity (for the channel input
signal) or output pin action control (for the channel output signal), as defined in
Table 24-100 . IPACA and
IPACB have the same format, where IPACA is related to Match A and first transition detection, and IPACB
to Match B and second transition detection. The same applies in analogue way to OPACA and OPACB.
For the output signal, configuring OPAC registers does not change the current signal state, but defines the
action to be done when a match or transition detection occurs. See
Section 24.5.5.2, Match Recognition ,
and Section 24.5.5.4.4, Channel Modes on Output Signal Generation , for more information.
IPACA/B = 1xx also enables assertion of MRLA/B during Time Slot Transition. See Section 24.5.5.2,
Match Recognition .
24.5.9.3.4 Immediate pin state control
It is possible to change output signal state immediately by using PSC (2 bits) and PSCS (1 bit) fields.
Table 24-99. Time Base Selection 2 – TBSB
TBSB bit 2 1 0
TBSB[3] = 0
Bitfield Comparator selection Capture selection Match TB selection
0 greater or equal TCR1 TCR1
1 equal-only TCR2 TCR2
TBSB[3] = 1
action
2 1 0
do nothing 1 1 1
reserved all other values
Table 24-100. Input and Output Pin Action Control – IPACA/B and OPACA/B
Value IPAC meaning OPAC meaning
000 Do not detect transitions Do not change output signal
001 Detect rising edge only Match
1
sets output signal high
010 Detect falling edge only Match
1
sets output signal low
011 Detect both edges Match
1
toggles output signal
100 Detect input signal = 0 on Match
1
1
Match A is used for IPACA/OPACA, and Match B for IPACB/OPACB.
Transition detection sets output signal low
101 Detect input signal = 1 on Match
1
Transition detection sets output signal high
110 reserved Transition detection toggles output signal
111 do not change IPAC do not change OPAC