MPC563XM Reference Manual, Rev. 1
Freescale Semiconductor
745
Preliminary—Subject to Change Without Notice
23.3.3
Time Base Registers
Time Base registers allows configuration and visibility of internally-generated time bases TCR1 and
TCR2. There is one of each of these registers for each eTPU Engine.
NOTE
Writes to this register issue bus error and are ineffective when MDIS=1.
Reads are always allowed.
23.3.3.1
ETPUTBCR - eTPU Time Base Configuration Register
This register configures several timebase options.
Figure 23-8. ETPUTBCR Register
TCR2CTL[2:0] — TCR2 Clock/Gate Control
These bits are part of the TCR2 clocking system (see
). They determine
the clock source for TCR2 before the prescaler. TCR2 can count on any detected edge of the TCRCLK
signal or use it for gating system clock divided by 8. After reset - TCRCLK signal rising edge is
selected. TCR2 can also be clocked by an internal peripheral timebase signal or system clock divided
by 8. TCR2CTL also determines the TCRCLK edge selected for angle tooth detection in angle mode.
See
eTPU 1: Base + 0x020 / eTPU 2: Base + 0x040
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
R
TCR2CTL
TCRCF
AM
0
0
0
TCR2P
W
RESET:
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
R
TCR1CTL
TCR1
CS
0
0
0
0
0
TCR1P
W
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Table 23-8. TCR2 Clock Source
TCR2CTL
AM = 0
TCR2 Clock before prescaler
AM = 1
Angle Tooth
detection
000
Gated DIV8 clock (system clock / 8). In this case, when the external TCRCLK
signal is low, the DIV8 clock is blocked, preventing it from incrementing the TCR2
prescaler. When the external TCRCLK signal is high, TCR2 prescaler is
incremented at the frequency of the system clock divided by 8.
do not use
with AM=1
001
Rise transition on TCRCLK signal increments the TCR2 prescaler.
rise edge
010
Fall transition on TCRCLK signal increments the TCR2 prescaler.
fall edge
011
Rise or Fall transition on TCRCLK signal increments the TCR2 prescaler.
both edges
100
DIV8 clock (system clock / 8)
do not use
with AM=1
101
Peripheral Timebase clock source