Frequency Modulated Phase Locked Loop and System Clocks (FMPLL)
MPC5565 Microcontroller Reference Manual, Rev. 1.0
Freescale Semiconductor
11-13
Address: Base + 0x0000
Access: User R/W
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
R
0
PREDIV
MFD
0
RFD
LOC
EN
LOL
RE
LOC
RE
W
Reset
0
0
0
0
0
0
0
1
0
0
0
1
0
0
0
0
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
R
DIS
CLK
LOL
IRQ
LOC
IRQ
RATE
DEPTH
EXP
W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 11-8. Synthesizer Control Register (FMPLL_SYNCR)
Table 11-4. FMPLL_SYNCR Field Descriptions
Field
Description
0
Reserved.
1–3
PREDIV[0:2]
The PREDIV bits control the value of the divider on the input clock. The output of the pre-divider circuit
generates the reference clock (F
prediv
) to the FMPLL analog loop. When the PREDIV bits are changed, the
FMPLL immediately loses lock. To prevent an immediate reset, the LOLRE bit must be cleared before writing
the PREDIV bits. In 1:1 (dual-controller) mode, the PREDIV bits are ignored and the input clock is fed directly
to the analog loop.
000 Divide by 1
001 Divide by 2
010 Divide by 3
011 Divide by 4
100 Divide by 5
101–111 Invalid values
Note:
Programming a PREDIV value such that the ICO operates outside its specified range causes
unpredictable results and the FMPLL does not lock. Refer to the device
Data Sheet
for details on the
ICO range.
Note:
To avoid unintentional interrupt requests, disable LOLIRQ before changing PREDIV and then reenable
it after acquiring lock.
Note:
When using crystal reference mode or external reference mode, The PREDIV value must not be set
to any value that causes the phase/frequency detector to go below 4 MHz. That is, the crystal
(F
ref_crystal
) or external clock (F
ref_ext
) frequency divided by the PREDIV value creates the F
prediv
frequency that must be greater than or equal to 4–20 MHz. Refer to the device
Data Sheet
for F
prediv
values.
Note:
To use the 8–20 MHz OSC, the PLL predivider must be configured for divide-by-two operation by tying
PLLCFG2 low (set PREDIV to 0b000).
Summary of Contents for MPC5565
Page 18: ...MPC5565 Microcontroller Reference Manual Devices Supported MPC5565 MPC5565 RM Rev 1 0 09 2007...
Page 34: ...MPC5565 Reference Manual Rev 1 0 Freescale Semiconductor 15...
Page 35: ...MPC5565 Reference Manual Rev 1 0 16 Freescale Semiconductor...
Page 553: ...Flash Memory MPC5565 Microcontroller Reference Manual Rev 1 0 13 38 Freescale Semiconductor...
Page 559: ...SRAM MPC5565 Microcontroller Reference Manual Rev 1 0 14 6 Freescale Semiconductor...
Page 973: ...Preface MPC5565 Microcontroller Reference Manual Rev 1 0 21 36 Freescale Semiconductor...
Page 1153: ...Calibration MPC5565 Microcontroller Reference Manual Rev 1 0 B 8 Freescale Semiconductor...
