参数资料
型号: MC56F8322MFAER2
厂商: FREESCALE SEMICONDUCTOR INC
元件分类: 数字信号处理
英文描述: 0-BIT, 120 MHz, OTHER DSP, PQFP48
封装: ROHS COMPLIANT, LQFP-48
文件页数: 61/136页
文件大小: 719K
代理商: MC56F8322MFAER2
56F8322 Techncial Data, Rev. 16
30
Freescale Semiconductor
Preliminary
3.3 Use of On-Chip Relaxation Oscillator
An internal relaxtion oscillator can supply the reference frequency when an external frequency source of
crystal is not used. During a boot or reset sequence, the relaxation oscillator is enabled by default, and the
PRECS bit in the PLLCR word is set to 0. If an external oscillator is connected, the relaxation oscillator
can be deselected instead by setting the PRECS bit in the PLLCR to 1. If a changeover between internal
and external oscillators is required at start up, internal device circuits compensate for any asynchronous
transitions between the two clock signals so that no glitches occur in the resulting master clock to the chip.
When changing clocks, the user must ensure that the clock source is not switched until the desired clock
is enabled and stable.
To compensate for variances in the device manufacturing process, the accuracy of the relaxation oscillator
can be incrementally adjusted to within + 0.1% of 8MHz by trimming an internal capacitor. Bits 0-9 of the
OSCTL (oscillator control) register allow the user to set in an additional offset (trim) to this preset value
to increase or decrease capacitance. Upon power-up, the default value of this trim is 512 units. Each unit
added or deleted changes the output frequency by about 0.1%, allowing incremental adjustment until the
desired frequency accuracy is achieved.
The internal oscillator is calibrated at the factory to 8MHz and the TRIM value is stored in the Flash
information block and loaded to the FMOPT1 register at reset. When using the relaxation oscillator, the
boot code should read the FMOPT1 register and set this value as OSCTL TRIM. For further information,
see the 56F8300 Peripheral User Manual.
3.4 Internal Clock Operation
At reset, both oscillators will be powered up; however, the relaxation oscillator will be the default clock
reference for the PLL. Software should power down the block not being used and program the PLL for the
correct frequency.
相关PDF资料
PDF描述
MC908AS60ACFNER 8-BIT, FLASH, 8.4 MHz, MICROCONTROLLER, PQCC52
MC9S08GB32ACFUER 8-BIT, FLASH, 40 MHz, MICROCONTROLLER, PQFP64
MC9S12C64CFAER 16-BIT, FLASH, 25 MHz, MICROCONTROLLER, PQFP48
MC9S12E256CFUE 16-BIT, FLASH, 25 MHz, MICROCONTROLLER, PQFP80
MC9S12GC96VPBER 16-BIT, FLASH, 25 MHz, MICROCONTROLLER, PQFP52
相关代理商/技术参数
参数描述
MC56F8322VFA60 功能描述:数字信号处理器和控制器 - DSP, DSC 60MHz 60MIPS RoHS:否 制造商:Microchip Technology 核心:dsPIC 数据总线宽度:16 bit 程序存储器大小:16 KB 数据 RAM 大小:2 KB 最大时钟频率:40 MHz 可编程输入/输出端数量:35 定时器数量:3 设备每秒兆指令数:50 MIPs 工作电源电压:3.3 V 最大工作温度:+ 85 C 封装 / 箱体:TQFP-44 安装风格:SMD/SMT
MC56F8322VFAE 功能描述:数字信号处理器和控制器 - DSP, DSC 16 BIT HYBRID CNTRLR RoHS:否 制造商:Microchip Technology 核心:dsPIC 数据总线宽度:16 bit 程序存储器大小:16 KB 数据 RAM 大小:2 KB 最大时钟频率:40 MHz 可编程输入/输出端数量:35 定时器数量:3 设备每秒兆指令数:50 MIPs 工作电源电压:3.3 V 最大工作温度:+ 85 C 封装 / 箱体:TQFP-44 安装风格:SMD/SMT
MC56F8322VFAER2 功能描述:数字信号处理器和控制器 - DSP, DSC 16 BIT HYBRID CNTRLR RoHS:否 制造商:Microchip Technology 核心:dsPIC 数据总线宽度:16 bit 程序存储器大小:16 KB 数据 RAM 大小:2 KB 最大时钟频率:40 MHz 可编程输入/输出端数量:35 定时器数量:3 设备每秒兆指令数:50 MIPs 工作电源电压:3.3 V 最大工作温度:+ 85 C 封装 / 箱体:TQFP-44 安装风格:SMD/SMT
MC56F8323 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:16-bit Digital Signal Controllers
MC56F8323EVM 功能描述:开发板和工具包 - 其他处理器 MC56F832X Dev Kit RoHS:否 制造商:Freescale Semiconductor 产品:Development Systems 工具用于评估:P3041 核心:e500mc 接口类型:I2C, SPI, USB 工作电源电压: