Enhanced Time Processing Unit (eTPU2)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
865
24.5.5.4.2
Channel modes overview
Predefined channel modes are divided according to the way they treat transitions in two basic modes:
•
Single Transition Modes
(mnemonic suffix
_st
): In these modes the first transition (flagged in
TDLA) issues a service request, and captures both time bases (selected by TBSA[1] and TBSB[1])
except on sm_st_e. The second transition (flagged in TDLB) does not issue a service request, but
it captures time base selected by TBSB[1], except on sm_st_e.
•
Double Transition Modes
(mnemonic suffix
_dt
): In these modes the second transition (flagged
in TDLB) issues a service request, and each transition captures its own selected time base
(Transition A and Transition B capture time bases selected by TBSA[1] and TBSB[1],
respectively).
In predefined modes, Transition B is always (but not only) enabled by Transition A, so that transitions are
always ordered: TDLA is set on the first transition and TDLB on the second. Unordered transitions are
possible with user-defined mode, when UDCM bit T1ET2 = 0. Matches are generally not ordered, except
on specific ordered match modes m2_o_st and m2_o_dt. Match capture(s) never overrides a Transition
capture, while Transition captures can always override a Match capture, either in predefined or
user-defined modes.
The following general rules apply to both predefined and user-defined modes:
•
Blocking of one Match by the other, when it occurs, is done through MRLEs.
•
Matches always block themselves by resetting their own MRLEs (Match A always blocks Match
A, Match B always blocks Match B).
Predefined modes differ mostly by the way matches affects and are affected by other matches and
transitions, as explained in next sections. However, some general rules on Match blocking apply:
•
Match B is blocked by first transition (TDLA) in single transition modes, and by second transition
(TDLB) in double transition modes.
•
Both Matches are blocked by first transition in single transition modes.
NOTE
The rules above and in following sections may be overruled by the state of
the channel latches if they are set/reset by microcode or if channel mode is
changed. Care must be taken to change channel modes, and is advisable to
reset channel flags MRLA/B, TDLA/B and MRLEA/B before writing
PDCM, or to UDCM when user-defined mode is selected.
Summary of Contents for MPC5644A
Page 2: ...MPC5644A Microcontroller Reference Manual Rev 6 2 Freescale Semiconductor...
Page 24: ...MPC5644A Microcontroller Reference Manual Rev 6 24 Freescale Semiconductor...
Page 26: ...MPC5644A Microcontroller Reference Manual Rev 6 26 Freescale Semiconductor...
Page 52: ...Introduction MPC5644A Microcontroller Reference Manual Rev 6 52 Freescale Semiconductor...
Page 56: ...Memory Map MPC5644A Microcontroller Reference Manual Rev 6 56 Freescale Semiconductor...
Page 1228: ...Decimation Filter MPC5644A Microcontroller Reference Manual Rev 6 1228 Freescale Semiconductor...
Page 1440: ...FlexCAN Module MPC5644A Microcontroller Reference Manual Rev 6 1440 Freescale Semiconductor...