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Operating Modes and Clocking
MPC5644A Microcontroller Reference Manual, Rev. 6
116
Freescale Semiconductor
The hold time for external bus pins can be changed by writing to SIU_ECCR[EBTS] (external bus tap
select bit).
NOTE
The CLKOUT pin is only available in the 324-pin package.
5.3.4.6.3
Nexus Message Clock (MCKO)
The Nexus message clock (MCKO) divider can be programmed to divide the system clock by two, four or
eight based on the MCKO_DIV field in the port configuration register (PCR) in the Nexus port controller
(NPC). The reset value of NPC_PCR[MCKO_DIV] selects an MCKO clock frequency one half of the
system clock frequency. The MCKO divider is configured by writing to the NPC through the JTAG port.
5.3.4.6.4
Engineering Clock Divider (ENGDIV)
The engineering clock divider (ENGDIV) can be programmed to divide system clock. This clock is mainly
used to clock some ASIC devices integrated on the board. There is no timing relation of this clock with
respect to any other clock in the design.
Refer to
Section 16.6.26, External Clock Control Register (SIU_ECCR)
for ENGDIV register bit
programming.
5.3.4.6.5
FlexCAN Clock Divider (CAN2:1)
The FlexCAN module has the ability to run from the system clock. It is possible, at the input to the
FlexCAN module, to perform a divide-by-1 or a divide-by-2 division of the system clock.
This FlexCAN system clock divider can be programmed by configuring the FlexCAN2:1 mode bit (field
SIU_SYSDIV[CAN_SRC]). The reset value is to divide-by-1.
The FlexCAN module does not support a divide-by-1 of the system clock above a certain frequency,
defined in the devicedatasheet. When running at maximum system frequency this setting will have to be
adjusted from its default value.
Содержание MPC5644A
Страница 2: ...MPC5644A Microcontroller Reference Manual Rev 6 2 Freescale Semiconductor...
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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...