Clocks and Power Control
MPC561/MPC563 Reference Manual, Rev. 1.2
8-30
Freescale Semiconductor
NOTE
COM[1] bit default value is determined during by BDRV reset
configuration bit; See
Section 7.5.2, “Hard Reset Configuration Word
MSB
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Field DBCT
COM
DCSLR MFPDL LPML TBS RTDIV
4
STBUC CQDS PRQEN RTSEL BUCS EBDF[0:1] LME
PORESET
1
0
ID2
1
0000
1
1
0
1
EQ2
2
0
ID[13:14]
1
EQ3
3
HRESET
U
0
ID2
1
Unaffected
1
Unaffected
ID[13:14]
1
U
Addr
0x2F C280
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
LSB
31
EECLK[0:1]
ENGDIV[0:5]
—
DFNL[0:2]
—
DFNH[0:2]
PORESET
0
0
1
1
1
1
1
1
0000_0000
HRESET
Unaffected
0000_0000
1
The hard reset value is a reset configuration word value, extracted from the indicated internal data bus lines. Refer to
“Hard Reset Configuration Word (RCW)
.”
2
EQ2 = MODCK1
3
EQ3 = (MODCK1 AND MODCK2 AND MODCK3) | (MODCK1 AND MODCK2 AND MODCK3) | (MODCK1 AND MODCK2 AND
.
4
RTDIV will be 0 if MODCK[1:3] = 000.
Figure 8-16. System Clock and Reset Control Register (SCCR)
Table 8-9. SCCR Bit Descriptions
Bits
Name
Description
0
DBCT
Disable backup clock for timers. The DBCT bit controls the timers clock source while the
chip is in limp mode. If DBCT is set, the timers clock (TMBLCK, PITRCLK) source will not
be the backup clock, even if the system clock source is the backup clock ring oscillator. The
real-time clock source will be EXTAL or EXTCLK according to RTSEL bit (see description
in bit 11 below), and the time base clocks source will be determined according to TBS bit
and MODCK1.
0 If the chip is in limp mode, the timer clock source is the backup (limp) clock
1 The timer clock source is either the external clock or the crystal (depending on the current
clock mode selected)
1:2
COM
Clock Output Mode – The COM and CQDS bits control the output buffer strength of the
CLKOUT and external bus pins. When both COM bits are set the CLKOUT pin is held in
the high (1) state and external bus pins are driven at reduced drive. These bits can be
dynamically changed without generating spikes on the CLKOUT and external bus pins. If
CLKOUT pin is not connected to external circuits, set both bits (disabling CLKOUT) to
minimize noise and power dissipation. The default value for COM[1] is determined by the
BDRV bit in the reset configuration word. See
. For CLKOUT control see
Summary of Contents for MPC561
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Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
Page 854: ...Time Processor Unit 3 MPC561 MPC563 Reference Manual Rev 1 2 19 24 Freescale Semiconductor...
Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...