
Operating Modes and Clocking
MPC5644A Microcontroller Reference Manual, Rev. 6
108
Freescale Semiconductor
Upon Reset, the system clock source is the oscillator clock with either crystal as reference or bypassed
based on the PLLREF pin value driven during system reset.
Please note the following:
1. RCOSC is never used as a source of system clock.
2. PHI1 output from PLL is never used as a source of system clock. It is used as one of the clock
sources for the FlexRay module.
3. See the FMPLL chapter for details on FMPLL operation.
5.3.3.1
Support for 150 MHz system clock generation
The oscillator and PLL support generation of a 150 MHz system clock while using the 40 MHz crystal
required for FlexRay operation. A possible PLL configuration is shown below:
•
Input clock (crystal frequency): 40 MHz
•
EPREDIV/IDF divider = /8 (1–15 range supported)
•
EMFD/NDIV loop divider = 60 (32–96 supported)
•
VCO clock out = 300 MHz (256–512 MHz range supported)
•
ERFD/ODF output divider = /2 (/2, /4, /8, /16 supported)
•
SYSDIV divider = /1 (/1, /2, /4, /8, /16 supported)
•
System clock = 150 MHz
5.3.3.2
Support for 100 MHz system clock generation
The oscillator and PLL support generation of a 100 MHz system clock while using the 40 MHz crystal
required fro FlexRay operation. A possible PLL configuration is shown below:
•
Input clock (crystal frequency): 40 MHz
•
EPREDIV/IDF divider = /8 (1–15 range supported)
•
EMFD/NDIV loop divider = 80 (32–96 supported)
•
VCO clock out = 400 MHz (256–512 MHz range supported)
•
ERFD/ODF output divider = /4 (/2, /4, /8, /16 supported)
•
SYSDIV divider = /1 (/1, /2, /4, /8, /16 supported)
•
System clock = 100 MHz
5.3.3.3
Support for FlexRay operation
The MPC5644A MCU supports generation of the clock signals needed for the operation of the FlexRay
module. Two options are supported for the generation of the FlexRay clock:
•
If the PLL is used with Frequency Modulation enabled, a 40 MHz crystal or external clock source
must be used to supply the FlexRay clock.
•
If the PLL is configured to generate a 120 MHz system clock without Frequency Modulation, then
the FlexRay module can be clocked from the system clock, allowing the use of other crystal
frequencies. In this mode of operation, the VCO frequency would be 480 MHz (256–512 MHz
Содержание MPC5644A
Страница 2: ...MPC5644A Microcontroller Reference Manual Rev 6 2 Freescale Semiconductor...
Страница 24: ...MPC5644A Microcontroller Reference Manual Rev 6 24 Freescale Semiconductor...
Страница 26: ...MPC5644A Microcontroller Reference Manual Rev 6 26 Freescale Semiconductor...
Страница 52: ...Introduction MPC5644A Microcontroller Reference Manual Rev 6 52 Freescale Semiconductor...
Страница 56: ...Memory Map MPC5644A Microcontroller Reference Manual Rev 6 56 Freescale Semiconductor...
Страница 130: ...Device Performance Optimization MPC5644A Microcontroller Reference Manual Rev 6 130 Freescale Semiconductor...
Страница 204: ...Multi Layer AHB Crossbar Switch XBAR MPC5644A Microcontroller Reference Manual Rev 6 204 Freescale Semiconductor...
Страница 212: ...Peripheral Bridge PBRIDGE MPC5644A Microcontroller Reference Manual Rev 6 212 Freescale Semiconductor...
Страница 558: ...System Integration Unit SIU MPC5644A Microcontroller Reference Manual Rev 6 558 Freescale Semiconductor...
Страница 582: ...Frequency modulated phase locked loop FMPLL MPC5644A Microcontroller Reference Manual Rev 6 582 Freescale Semiconductor...
Страница 766: ...Enhanced Time Processing Unit eTPU2 MPC5644A Microcontroller Reference Manual Rev 6 766 Freescale Semiconductor...
Страница 1228: ...Decimation Filter MPC5644A Microcontroller Reference Manual Rev 6 1228 Freescale Semiconductor...
Страница 1236: ...System Information Module and Trim SIM MPC5644A Microcontroller Reference Manual Rev 6 1236 Freescale Semiconductor...
Страница 1250: ...Cyclic Redundancy Checker CRC Unit MPC5644A Microcontroller Reference Manual Rev 6 1250 Freescale Semiconductor...
Страница 1336: ...Deserial Serial Peripheral Interface DSPI MPC5644A Microcontroller Reference Manual Rev 6 1336 Freescale Semiconductor...
Страница 1388: ...Enhanced Serial Communication Interface ESCI MPC5644A Microcontroller Reference Manual Rev 6 1388 Freescale Semiconductor...
Страница 1440: ...FlexCAN Module MPC5644A Microcontroller Reference Manual Rev 6 1440 Freescale Semiconductor...
Страница 1624: ...FlexRay Communication Controller FlexRay MPC5644A Microcontroller Reference Manual Rev 6 1624 Freescale Semiconductor...
Страница 1670: ...JTAG Controller JTAGC MPC5644A Microcontroller Reference Manual Rev 6 1670 Freescale Semiconductor...
Страница 1692: ...Nexus Port Controller NPC MPC5644A Microcontroller Reference Manual Rev 6 1692 Freescale Semiconductor...
Страница 1701: ...Development Trigger Semaphore DTS MPC5644A Microcontroller Reference Manual Rev 6 Freescale Semiconductor 1701...
Страница 1702: ...Development Trigger Semaphore DTS MPC5644A Microcontroller Reference Manual Rev 6 1702 Freescale Semiconductor...