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MCF5253 Introduction
MCF5253 Reference Manual, Rev. 1
Freescale Semiconductor
1-13
The MCF5253 supports voltage controlled crystal oscillator (VCXO) operation of the oscillator by means
of a 16-bit pulse density modulation output. Using this mode, it is possible to lock the oscillator to the
frequency of an incoming IEC958 or IIS signal. The maximum trim depends on the type and design of the
oscillator. Typically a trim of +/- 100 ppm can be achieved with a crystal oscillator and over +/- 1000 ppm
with an LC oscillator.
1.5.30
Sleep and Wake-Up Modes
The MCF5253 has a low power Sleep mode where all clocks are disabled and SRAM contents are
maintained. Sleep mode is exited by taking the external Wake-up pin low. Sleep mode is selected by
software control of a bit in the PLL register. When Sleep mode is exited code execution resumes from the
next instruction.
1.5.31
Bootloader
The MCF5253 incorporates a ROM Bootloader, which enables booting from UART, I
2
C, SPI or IDE
devices.
1.5.32
Internal Voltage Regulator
An internal 1.2 V regulator can be used to supply the CPU and PLL sections of the MCF5253, reducing
the number of external components required and allowing operation from a single supply rail, typically 3.3
volts. However, it must be noted that the internal regulator has an efficiency of less than 50%, and it is not
intended for use in battery powered applications, where the use of a highly efficient external DC-DC
converter would be more appropriate.
Содержание MCF5253
Страница 1: ...Document Number MCF5253RM Rev 1 08 2008 MCF5253 Reference Manual...
Страница 26: ...MCF5253 Reference Manual Rev 1 xxvi Freescale Semiconductor...
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Страница 46: ...MCF5253 Introduction MCF5253 Reference Manual Rev 1 1 14 Freescale Semiconductor...
Страница 62: ...Signal Description MCF5253 Reference Manual Rev 1 2 16 Freescale Semiconductor...
Страница 98: ...Instruction Cache MCF5253 Reference Manual Rev 1 5 10 Freescale Semiconductor...
Страница 104: ...Static RAM SRAM MCF5253 Reference Manual Rev 1 6 6 Freescale Semiconductor...
Страница 128: ...Synchronous DRAM Controller Module MCF5253 Reference Manual Rev 1 7 24 Freescale Semiconductor...
Страница 144: ...Bus Operation MCF5253 Reference Manual Rev 1 8 16 Freescale Semiconductor...
Страница 176: ...System Integration Module SIM MCF5253 Reference Manual Rev 1 9 32 Freescale Semiconductor...
Страница 198: ...Analog to Digital Converter ADC MCF5253 Reference Manual Rev 1 12 6 Freescale Semiconductor...
Страница 246: ...DMA Controller MCF5253 Reference Manual Rev 1 14 18 Freescale Semiconductor...
Страница 282: ...UART Modules MCF5253 Reference Manual Rev 1 15 36 Freescale Semiconductor...
Страница 298: ...Queued Serial Peripheral Interface QSPI Module MCF5253 Reference Manual Rev 1 16 16 Freescale Semiconductor...
Страница 344: ...Audio Interface Module AIM MCF5253 Reference Manual Rev 1 17 46 Freescale Semiconductor...
Страница 362: ...I2 C Modules MCF5253 Reference Manual Rev 1 18 18 Freescale Semiconductor...
Страница 370: ...Boot ROM MCF5253 Reference Manual Rev 1 19 8 Freescale Semiconductor...