PXR40RM Datasheet, PDF (1198/1434 Pages) Freescale Semiconductor, Inc – PXR40 Microcontroller

Enhanced Time Processing Unit (eTPU2)
TCR1CTL is part of the TCR1 clocking system (see Section 29.3.5, Time Bases). It determines, together
with TCR1CS, the clock source for TCR1. TCR1 can count on detected rising edge of the TCRCLK signal,
the eTPU clock, or the eTPU clock divided by 2 (see Table 29-11). After reset TCRCLK signal is selected
TCR1CS - TCR1 Clock Source
TCR1CS provides the option to double the TCR1 incrementing speed, using eTPU clock as its clock
source instead of eTPU clock / 2.
1 = use eTPU clock as TCR1 clock source before the prescaler; can only be set in specific
combinations with TCR1CTL (see Table 29-11).
0 = use eTPU 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 eTPU
Reference Manual for details).
NOTE
The clock source of the EAC angle tick generator will still be an even
division of eTPU clock if TCR1CS=1, obeying to the fields TCR1P as if
TCR1CS=0 (see eTPU Reference Manual for details).
Table 29-11. TCR1 Clock Source
TCR1CTL TCR1CS¹
TCR1 Clock before prescaler
00
0
selects TCRCLK as clock source for the TCR1 prescaler²
10
0
selects eTPU clock divided by 2 as clock source for the TCR1 prescaler
10
1
selects eTPU clock as clock source for the TCR1 prescaler
11
0
TCR1 frozen, except as a STAC client;
1 _{All other combinations of TCR1CTL and TCR1CS are reserved.}
2 _{This selection must not be used in Angle Mode.}
TCR1P[0:7] — Timer Count Register 1 Prescaler Control
TCR1 is clocked from the output of a prescaler. The input to the prescaler is the internal eTPU clock
divided by 2, eTPU clock, or the output of TCRCLK filter. The prescaler divides this input by
(TCR1P+1) allowing frequency divisions from 1 up to 256.
29-30
PXR40 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor