NXP Semiconductors MPC5644A, Reference Manual, Page: 896 / 1735

Enhanced Time Processing Unit (eTPU2)
MPC5644A Microcontroller Reference Manual, Rev. 6
896 Freescale Semiconductor
24.5.7.2.2 TCR2 – Timer Counter 2
In Angle Mode TCR2 counts angle ticks instead of time.
12
IPH
Insert Physical Tooth
This bit generates a dummy physical tooth which has the same effect as a real physical tooth, and resets
itself subsequently. If EAC is in Halt mode, it switches back to Normal mode
1
. If EAC is in Normal Mode,
it switches to High Rate Mode. If Angle Logic is frozen by HOLD = 1 (see below), it returns to the state it
was at the freezing moment.
No Operation.
Insert dummy physical tooth.
IPH reads as 1 in the next microinstruction after it is asserted, negating subsequently. However, it can be
set twice in two consecutive microinstructions to generate two teeth and make the EAC go from Halt to
Normal to High Rate Mode.
13-14
MISSCNT
Missing Tooth Counter
Decremented on each estimated tooth, stops at zero. Used for generation of “Dummy Tooth” whenever it
holds a non-zero value.
00No missing tooth
01One missing tooth
10Two missing teeth
11Three missing teeth
If the tooth is detected or inserted before the missing tooth tick count completes (going High Rate mode,
see
Section 24.5.7.5.3, High rate mode (Acceleration) ), MISSCNT resets immediately, but missing teeth
count continues in High Rate mode (see Section 24.5.7.12.1, TPR buffering ).
15
LAST
Last Tooth Indication
Asserted by microcode and negated when a tooth is detected or inserted via IPH.
Not Last Tooth.
Last Tooth - reset TCR2 Counter at the end of the tooth tick count (after physical tooth or IPH = 1) when
MISSCNT = 0.
If the tooth is detected or inserted before the tooth tick count completes (going High Rate mode, see
Section 24.5.7.5.3, High rate mode (Acceleration) ), LAST resets immediately, but TCR2 resets only when
the tooth count completes and MISSCNT = 0
1
Missing a physical tooth naturally causes EAC to get into Halt mode.
Field Description