NXP Semiconductors MPC5644A, Reference Manual, Page: 784 / 1735

Enhanced Time Processing Unit (eTPU2)
MPC5644A Microcontroller Reference Manual, Rev. 6
784 Freescale Semiconductor
10-15 TCR2P[5:0]—Timer Count Register 2 Prescaler Control
These bits are part of the TCR2 clocking system (see Section 24.5.6, Time Bases ). TCR2 is clocked from
the output of a prescaler. The prescaler divides its input by (TCR2P+1) allowing frequency divisions from
1 to 64. The prescaler input is the system clock divided by 8 (in gated or non-gated clock mode), or Internal
Timebase input, or TCRCLK filtered input. This field has no effect on TCR2 in Angle Mode.
16-17 TCR1CTL—TCR1 Clock/Gate Control
TCR1CTL is part of the TCR1 clocking system (see Section 24.5.6, Time Bases ). It determines, together
with TCR1CS, the clock source for TCR1. TCR1 can count on detected rising edge of the TCRCLK signal,
a Peripheral Timebase source, system clock, or the system clock divided by 2 (see
Table 24-17 ). After
reset TCRCLK signal is selected
18 TCR1CS—TCR1 Clock Source
TCR1CS provides the option to double the TCR1 incrementing speed, using system clock as its clock
source instead of system clock / 2.
1: use system clock as TCR1 clock source before the prescaler; can only be set in specific combinations
with TCR1CTL (see
Table 24-17 ).
0: use system clock / 2 as TCR1 clock source before the prescaler, if that clock source is selected by
TCR1CTL.
Note: TCR1CS = 1 also makes the channel work on T2/T4 timing mode (see Section 24.5.5.7.2, T2/T4
Channel Timing ).
Note: The clock source of the EAC angle tick generator will still be an even division of system clock if
TCR1CS = 1, obeying to the fields TCR1P as if TCR1CS = 0 (see
Section 24.5.7.4, Angle tick
generator ).
19-23 Reserved
Table 24-13. ETPU_TBCR field description (continued)
Field Description
Table 24-17. TCR1 clock source
TCR1CTL TCR1CS
1
1
All other combinations of TCR1CTL and TCR1CS are reserved.
TCR1 Clock before prescaler
00 0 selects TCRCLK as clock source for the TCR1 prescaler
2
2
This selection must not be used in Angle Mode.
01 0 selects Peripheral Timebase clock as source for the TCR1
prescaler
10 0 selects system clock divided by 2 as clock source for the
TCR1 prescaler
10 1 selects system clock as clock source for the TCR1 prescaler
11 0 TCR1 frozen, except as a STAC client;